Modulating nudix homology domain (nhd) with nicotinamide mononucleotide analogs and derivatives of same

ABSTRACT

The invention provides methods of modulating and regulating NHD protein-protein interactions through nicotinamide mononucleotide, analogs and derivatives thereof, such as NAD+. Such modulation may be useful in methods of treating and preventing cancer, aging, cell death, radiation damage, radiation exposure, among others, may improve DNA repair, cell proliferation, cell survival, among others, and may increase the life span of a cell or protect it against certain stresses, among others

RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Application Ser. No. 62/442,247, filed Jan. 4, 2017. This application is hereby incorporated herein by reference in its entirety.

GOVERNMENT INTEREST

This invention was made with Government support under National Institutes of Health Grant AG019719 and AG028730. The Government has certain rights in the invention.

BACKGROUND OF THE INVENTION

Nicotinamide adenine dinucleotide (NAD⁺) is critical for redox reactions and as a substrate for signaling by the poly(ADP-ribose) polymerases (PARPs) and the sirtuins (SIRT1-7) in the regulation of DNA repair, energy metabolism, cell survival, circadian rhythms, among others (R. H. Houtkooper et al. Endocr. Rev. 31, 194-223 (2010); M. S. Bonkowski et al. Nat. Rev. Mol. Cell Biol. 17, 679-690 (2016); S. Imai et al. Trends Cell Biol. 24, 464-471 (2014)). Raising NAD⁺ concentrations or directly activating the sirtuins delays aging in yeast, flies, and mice (L. Mouchiroud et al. Cell 154, 430-441 (2013); J. Yoshino et al. Cell Metab. 14, 528-536 (2011); K. S. Bhullar et al. Biochim. Biophys. Acta 1852, 1209-1218 (2015)). Increased amounts of sirtuin and PARP1 activity are also associated with improved health and longevity in humans (L. Mouchiroud et al. Cell 154, 430-441 (2013); K. Grube et al. Proc. Natl. Acad. Sci. U.S.A. 89, 11759-11763 (1992)). How cells modulate NAD⁺ and PARP1 activity may impact diabetes, cancer, and possibly aging (S. Imai et al. Trends Cell Biol. 24, 464-471 (2014); M. C. Haigis et al. Annu. Rev. Pathol. 5, 253-295 (2010)). Whether NAD⁺ has a third role in cells as a direct regulator of protein-protein interactions is a matter of speculation (V. Anantharaman et al. Cell cycle 7, 1467-1472 (2008)). Numerous proteins possess Nudix homology domains (NHDs) that have no known function. Understanding the mechanism and interplay of NAD+ and NHDs may shed light on the regulation of DNA repair, energy metabolism, cell survival, among others, and provide novel methods and therapies for major diseases such as cancer, radiation, and aging, among others.

SUMMARY OF THE INVENTION

The present invention is based, at least in part, on the discovery that Nudix homology domains (NHDs) are nicotinamide adenine dinucleotide (NAD⁺) binding domains that regulate protein-protein interactions. Through NHDs, NAD⁺ may directly regulate protein-protein interactions, the modulation of which may be useful in methods of recovering from, treating, and preventing cancer, aging, cell death, radiation damage, radiation exposure, among others, may improve DNA repair, cell proliferation, cell survival, among others, and may increase the life span of a cell or protect it against certain stresses, among others.

One aspect of the invention relates to a method for recovering from, treating, or preventing cancer in a subject in need thereof comprising administering an effective amount of a) nicotinamide mononucleotide, or an analog or derivative thereof; b) an agent that increases the level of nicotinamide mononucleotide, or an analog or derivative thereof; or c) both a) and b); to the subject to thereby modulate the activity of a biologically active polypeptide comprising a Nudix homology domain (NHD), or fragment thereof, or a nucleic acid encoding same.

Another aspect of the invention relates to a method for recovering from, treating, or preventing aging or cell death in a subject in need thereof comprising administering an effective amount of a) nicotinamide mononucleotide, or an analog or derivative thereof; b) an agent that increases the level of nicotinamide mononucleotide, or an analog or derivative thereof; or c) both a) and b); to the subject to thereby modulate the activity of a biologically active polypeptide comprising a Nudix homology domain (NHD), or fragment thereof, or a nucleic acid encoding same.

Another aspect of the invention relates to a method for recovering from, treating, or preventing radiation damage or radiation exposure or in a subject in need thereof comprising administering an effective amount of a) nicotinamide mononucleotide, or an analog or derivative thereof; b) an agent that increases the level of nicotinamide mononucleotide, or an analog or derivative thereof; or c) both a) and b); to the subject to thereby modulate the activity of a biologically active polypeptide comprising a Nudix homology domain (NHD), or fragment thereof, or a nucleic acid encoding same.

Another aspect of the invention relates to a method for recovering from, treating, or preventing chemotherapy-induced damage or cellular senescence in a subject in need thereof comprising administering an effective amount of a) nicotinamide mononucleotide, or an analog or derivative thereof; b) an agent that increases the level of nicotinamide mononucleotide, or an analog or derivative thereof; or c) both a) and b); to the subject to thereby modulate the activity of a biologically active polypeptide comprising a Nudix homology domain (NHD), or fragment thereof, or a nucleic acid encoding same.

Another aspect of the invention relates to a method for modulating DNA repair in a subject in need thereof comprising administering an effective amount of a) nicotinamide mononucleotide, or an analog or derivative thereof; b) an agent that increases the level of nicotinamide mononucleotide, or an analog or derivative thereof; or c) both a) and b); to the subject to thereby modulate the activity of a biologically active polypeptide comprising a Nudix homology domain (NHD), or fragment thereof, or a nucleic acid encoding same.

Another aspect of the invention relates to a method for modulating cell proliferation or cell survival in a subject in need thereof comprising administering an effective amount of a) nicotinamide mononucleotide, or an analog or derivative thereof; b) an agent that increases the level of nicotinamide mononucleotide, or an analog or derivative thereof; or c) both a) and b); to the subject to thereby modulate the activity of a biologically active polypeptide comprising a Nudix homology domain (NHD), or fragment thereof, or a nucleic acid encoding same.

In some embodiments of any of the aforementioned methods, said biologically active polypeptide comprising a Nudix homology domain (NHD), or fragment thereof, binds nicotinamide dinucleotide, or an analog or derivative thereof.

In some embodiments of any of the aforementioned methods, said nicotinamide mononucleotide, or an analog or derivative thereof is nicotinamide adenine dinucleotide (NAD+).

In some embodiments of any of the aforementioned methods, said biologically active polypeptide comprising a Nudix homology domain (NHD), or fragment thereof, comprises the NHD domain of a protein from Deleted Breast Cancer 1 (DBC1), or a protein set forth in Table 3.

In some embodiments of any of the aforementioned methods, said biologically active polypeptide comprising a Nudix homology domain (NHD), or fragment thereof, has a defective, deleted, or mutated protein binding region which inhibits interaction with a protein involved in cancer, aging, radiation damage, DNA repair, cell proliferation, or cell survival.

In some embodiments of any of the aforementioned methods, said biologically active polypeptide comprising a Nudix homology domain (NHD), or fragment thereof, has a defective, deleted, or mutated protein binding region which inhibits interaction with a protein involved in regulating of gene expression, cell cycle, or both, wherein said protein comprises a protein set forth in Table 4.

In some embodiments, the protein involved in regulating of gene expression is selected from the group consisting of proteins involved in RNA processing, translation, transcription, RNA splicing, spliceosomal complex, signal transduction, chromatin remodeling, immune response, trafficking, transcriptional regulation, and circadian cycle. In some embodiments, the protein involved in regulating cell cycle is selected from the group consisting of proteins involved in proliferation, chromosome condensation, chromosome segregation, DNA damage response, DNA replication, metabolism, nuclear trafficking, immune response.

In some embodiments of any of the aforementioned methods, said protein is selected from the group consisting of PARP1, HNRPLL, SON, SUGP2, WDR33, THOC5, PUS1, SYMPK, THOC2, SART3, LSM4, PLRG1, SF3B2, SNRNP40, XAB2, ZCCHC8, PRPF8, PRPF4, POLR3B, POLR1A, POLR2D, POLR2A, SUPT5H, SUPT6H, GT3C4, EXOSC7, EIF4H, GTF3C5, MRPS23, SEP15, FKBP5, MRPS34, TPX2, TRIM27, USP7, UBE2K, STAG2, PDS5B, SMC4, PDS5A, NCAPG2, AKAP8, NUMA1, CEP170, POGZ, CTR9, TBLXR1, G3BP1, TLE1, SPIN1, COPS3, TLE3, GPS1, CSNK2A1, PRKDC, MSH3, MSH6, POLA1, TMPO, FEN1, PRIM2, CHTF18, AKAP8L, MLF2, SPATA5, ZMPSTE24, SMARCA2, SIRT1, SMARCA4, ARID1A, SMARCC2, KDM3B, ADNP, HDAC3, VPRBP, LCP1, KPNA3, TOMM40, IPO9, TIMM13, COBRA1, SAFB2, PELP1, TCEB2, CDK9, TROVE2, SRRT, PSPC1, FAM98B, GK, TXNRD1, NADKD1, NDUFS2, PCK2, CISD1, CYC1, and UQCRFS1, or combination thereof.

In some embodiments of any of the aforementioned methods, said protein is selected from the group consisting of PARP1, MATR3, SRRT, NOP56, RIP1L1, UPF1, ZC3H14, HNRNPA0, LRPPRC, FARSA, EIF3D, MRPS22, NOP2, DNAJA2, NSUN2, DNAJA3, DDX5, DHX9, SFPQ, PPP1CB, PPP2R1A, BUB3, ILF3, ADAR, ISG15, NUP155, ZFR, ZC3H11A, KPNA4, KPNA1, KPNA3, KPNA6, ZNF326, SKIV2L2, SON, SUGP2, WTAP, PTBP1, PTBP3, CPSF1, RBM4, HNRNPUL2, SF1, SF3B1, PNN, ZCCHC8, SF3B3, CDC5L, PRPF8, SNRNP200, SAFB, PRMT5, WDR77, SUPT16H, SIRT1, SAP18, IKZF1, HCFC1, HDAC3, ZNF281, ZNF318, GIGYF2, RBM14, SAFB2, SPIN1, GTF21, MCM3, AKAP8L, TRIM28, PSMA2, PSME3, PSMB3, p53, USP11, SLC25A6, PFAS, CAD, SLC25A3, PFKL, ACLY, PPHLN1, RBM12B, and FLNA, or combination thereof.

In some embodiments of any of the aforementioned methods, the agent is an NAD+ precursor.

In some embodiments, the NAD+ precursor is nicotinamide mononucleotide (NMN) or a salt thereof, or a prodrug thereof, including crystalline and polymorphic form of same.

In some embodiments of any of the aforementioned methods, the agent decreases or reduces nicotinamide.

In some embodiments of any of the aforementioned methods, the agent increases the level or activity of an enzyme involved in NAD+ biosynthesis, or an enzymatically active fragment thereof, or a nucleic acid encoding an enzyme involved in NAD+ biosynthesis, or an enzymatically active fragment thereof.

In some embodiments, the enzyme is mononucleotide adenylyl transferase (NMNAT) or nicotinamide phosphoribosyl transferase (NAMPT or NAMPRT).

In some embodiments of any of the aforementioned methods, said method further comprises administering an inhibitor that blocks or prevents protein-protein interaction or binding of said biologically active polypeptide comprising a NHD, or fragment thereof, with said protein involved in cancer, aging, radiation damage, DNA repair, cell proliferation, or cell survival.

In some embodiments of any of the aforementioned methods, the agent is administered at a dose of between 0.5-5 grams per day.

In some embodiments of any of the aforementioned methods, the agent is administered conjointly, prior to, or subsequent to administrating the biologically active polypeptide comprising the NHD, or fragment thereof, or a nucleic acid encoding same.

In some embodiments of any of the aforementioned methods, the agent or the biologically active polypeptide comprising the NHD, or fragment thereof, or a nucleic acid encoding same is administered in a pharmaceutically effective amount.

In some embodiments, the pharmaceutically effective amount is provided as a pharmaceutical composition in combination with a pharmaceutically-acceptable excipient, diluent, or carrier.

In some embodiments, the subject is a mammal or non-mammal.

In some embodiments, the subject is a human.

Other objects, features and advantages of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts regulation of the PARP1-DBC1 interactions by NAD⁺. FIG. 1, Panel (A) shows endogenous DBC1 and PARP1 interact. FIG. 1, Panel (B) shows that NAD⁺ dissociates the PARP1-DBC1 interaction. FIG. 1, Panel (C) shows the effect of NAD⁺ and structurally related molecules on the PARP1-DBC1 interaction. Flag-DBC1 was incubated with molecules (200 μM) for 1 hr then probed for PARP1. FIG. 1, Panels D to F show the PARP1-DBC1 interaction after FK866 (Panel (D)) or NMN (Panel (E)) treatments for 24 hrs, or in cells overexpressing NMNAT1, an NAD salvage pathway gene (Panel F) to raise NAD⁺, mean±SEM, (Panel (D)) and (Panel (E)), one-way ANOVA, Sidak's post-hoc correction; (Panel (F)), unpaired two-tailed t-test, *p<0.05, ****p<0.0001.

FIG. 2 depicts binding of the Nudix homology domain (NHD) of DBC1 to NAD⁺ and PARP1. FIG. 2, Panel (A) shows the domains and crystallographic-based homology model of the NHD docked with NAD⁺. Abbreviations: S1-like, ribosomal protein S1 OB-fold domain-like; EF, EF-hand; LZ, leucine zipper. Residues predicted to be in the vicinity of bound NAD⁺ are highlighted. FIG. 2, Panel (B) shows the interaction of V5/His-tagged DBC1 mutants and PARP1. See FIG. 12 for additional mutants. Panels (C) and (D) show the direct binding of NAD⁺ to the DBC1-NHD, assessed using a radiolabeled NAD⁺ binding assay (Panel (C)) or a biotin-NAD⁺ binding assay (Panel (D)), mean±SEM, one-way ANOVA, Sidak's post-hoc correction, ***p<0.001, n.s., not significant. Panel (E) depicts the effect of NAD⁺ on binding of DBC1-NHD mutants to PARP1.

FIG. 3 depicts DBC1 inhibits PARP1 activity and DNA repair. FIG. 2, Panel (A) shows inhibition of PARP1 activity by DBC1 purified from 293T cells. FIG. 2, Panel (B) shows PAR (polyADP-ribose) abundance in 293T cells lacking DBC1. FIG. 2, Panel (C) shows opposing effects of re-introducing wild-type or DBC1_(Q391A) into MCF-7 cells on mRNA of PARP1-regulated genes: TMSNB (Thymosin beta), PEG10 (Paternally expressed gene 10) and NELL2 (Neural EGFL-like 2). ABHD2 was a negative control. DBC1 and PARP1 abundance are shown in FIG. 14, Panel (E). FIG. 2, Panel (D) shows γ-H2AX abundance in DBC1 knockdown cells after paraquat treatment (1 mM, 24 hrs). FIG. 2, Panel (E) shows DNA fragmentation after paraquat treatment (0.5 mM, 24 hrs) in DBC1 knockdown cells, assessed by a comet assay, >50 cells/group. See FIG. 15, Panel (A). FIG. 2, Panel (F) shows DNA break repair (NHEJ and HR) in DBC1 knockdown cells treated with paraquat (1 mM) or 3-AB (5 mM), n=3 biological replicates. FIG. 2, Panel (G) shows protection of human primary fibroblasts from DNA damage (300 μM paraquat) by NMN (500 μM). 100±20 cells/condition, n=4 biological replicates (2 cell lines, 2× for each), 24 hrs treatment. See FIG. 16. Errors are SEM, one-way ANOVA (Panels (C) and (G)) and two-way ANOVA (Panels (E) and (F)), Sidak's post-hoc correction, *p<0.05, **p<0.01, ***p<0.001, ****p<0.0001, n.s., not significant.

FIG. 4 depicts increases in the PARP1-DBC1 complex and DNA damage with age are reversed by NMN, a precursor to NAD⁺. FIG. 4, Panels (A) and (B) show NAD⁺ concentrations and PARP1-DBC1 interactions in livers of young and old mice (6 vs. 22 months, n=3/group). FIG. 4, Panel (C) shows γH2AX foci (red arrow) in the livers of young (6 month, Y) and old mice (30 months, 0) (n=3/group) treated for 7 days with vehicle (PBS) or NMN (500 mg/kg/day i.p., n=3/group). FIG. 4, Panels (D) and (E) show NAD⁺ concentrations and PARP1-DBC1 interactions in the livers of old mice (22 months) treated as in (Panel (C)). FIG. 4, Panel (E) shows γH2AX foci (red arrow) in the livers of young (6 month, Y) and old mice (30 months, 0) (n=3/group) treated as in (Panel (C)). FIG. 4, Panel (F) shows PARP1 activity in young (6 months, n=4) and old (26±4 months, n=8/group) mice. FIG. 4, Panel (G) shows PARP1 activity in 18-20 month old DBC1 knockout mice livers (n=3-4). FIG. 4, Panel (H) shows γH2AX abundance in the livers of 26-month olds after irradiation (IR) (7.5 Gy, ¹³⁷CsCl) treated as in (Panel (C)) (n=3/group). FIG. 4, Panel (I) shows blood counts of 23-month olds on the 7-8th days after irradiation (n=10 per group). See FIG. 22, Panels (A) and (B). FIG. 4, Panel (J) shows blood metrics of 4-month olds with a single oral dose of NMN (2000 mg/kg) 1 hr after irradiation (8 Gy, ¹³⁷CsCl) followed by another 7 days (2000 mg/kg/d, n=5-8/group). See FIG. 22, Panel (C). Errors are SEM, (Panels (A) to (D)) and (Panel (G)) are unpaired two-tailed t-test; (Panel (E)), (Panel (F)) and (Panel (H)) are one-way ANOVA, Sidak's post-hoc correction; (Panels (I) and (J)), Mann-Whitney U-test, *p<0.05, **p<0.01, ****p<0.0001.

FIG. 5 contains 5 panels, Panels (A)-(E), depicting that PARP1-DBC1 complex formation is independent of SIRT1 or PARP1 activity. FIG. 5, Panel (A) shows PARP1-DBC1 interaction in the presence the SIRT1 inhibitor EX527 (20 μM, 24 hrs). FIG. 5, Panel (B) shows the effect of SIRT1 knockdown on the PARP1-DBC1 complex. FIG. 5, Panel (C) shows the PARP1-DBC1 interaction in the presence of the PARP1 inhibitors PJ34 (10 μM) or 3-AB (2 mM) for 24 hrs, bottom panel showing inhibitory effect of 3-AB (2 mM) on PAR induced by paraquat (0.5 mM). FIG. 5, Panel (D) shows the effect of overexpressing MACROD1 on the PARP1-DBC1 complex. DNA transfections: +=1 μg; ++=2 μg. FIG. 5, Panel (E) shows the interaction of catalytically inactive PARP1-E988K with DBC1, E988K lacks PAR modification ability, as tested in the bottom panel. All experiments were performed in 293T cells.

FIG. 6 contains 6 panels, Panels (A)-(F), depicting the effect of NAD⁺ on the PARP1-DBC1 complex. FIG. 6, Panels (A) to (C) show the PARP1-DBC1 interaction in the presence of molecules structurally related to NAD⁺: NAM (500 μM) and its analogue 3-AB (2 mM), adenine (200 μM), adenosine (200 μM), ATP (200 μM), or ADP-ribose (low=200 μM; high=500 μM). Flag-DBC1 immunoprecipitates bound to M2 beads were incubated with the above molecules for 1 hr, followed by assessment of PARP1 binding by western blotting. FIG. 6, Panel (D) shows the effect of NAD⁺ on the interaction between catalytically inactive PARP1-E988K and DBC1. FIG. 6, Panel (E) shows the effect of PARG (2 ng) or MACROD1 (1 μg) on the PARP1-DBC1 complex. The activity of self-purified MACROD1 was tested in the bottom panel: E988K-PARP1 was mono-ADPribosylated using biotin-NAD⁺ as described (Z. Mao et al. (2011) Science 332, 1443-1446), then de-ADPribosylated by incubating with 1 ug MacroD1 for 30 min as described (F. Rosenthal et al. (2013) Nat. Struc. Mol. Biol. 20, 502-507). FIG. 6, Panel (F) shows the effect of carba-NAD, a non-hydrolysable NAD⁺ analogue, on the PARP1-DBC1 complex.

FIG. 7 contains 3 panels, Panels (A)-(C),showing the effects of NAD⁺ levels and DNA damage on the interactions of DBC1 with PARP1. FIG. 7, Panel (A) shows that the treatment of 293T cells with nicotinamide riboside (NR) raises cellular NAD⁺ levels and dissociates PARP1-DBC1 complex (mean±SEM, unpaired two-tailed t-test, ***p<0.001). FIG. 7, Panel (B) shows the effect of paraquat treatment (24 hrs) on the PARP1-DBC1 complex. FIG. 7, Panel (C) shows the effect of the NAMPT inhibitor FK866 (5 nM, 24 hrs) on the SIRT1-DBC1 interaction.

FIG. 8 contains 4 panels, Panels (A)-(D), depicting that the PARP1-DBC1 interaction requires the NHD. FIG. 8, Panel (A) shows the DBC1 deletion mutants. Yellow-colored mutants were expressed in 293T cells. Blue-colored mutants could not be expressed. FIG. 8, Panels (B) and (C)) shows the expression of DBC1₍₂₄₃₋₉₂₃₎, DBC1₍₁₋₅₀₀₎, DBC1 ₍₁₋₃₃₀₎, DBC1₍₁₋₂₆₉₎ and DBC1 ₍₂₄₃₋₄₆₂₎ in 293T cells. FIG. 8, Panel (D) shows the interaction between PARP1 and DBC1 _((Δ354-396)), a form of DBC1 lacking partially the NHD.

FIG. 9 contains 2 panels, Panels (A)-(B), depicting direct binding of DBC1 to PARP1. FIG. 9, Panel (A) shows binding of recombinant human PARP1-ACAT (residues 1 to 654) to human DBC1 (residue 239 to 553) on blue native poly acrylamide gel electrophoresis in the presence or absence of PARG or MACROD1. FIG. 9, Panel (B) shows mass spectrometry on the three excised bands from lane 5, 11 and 12 at the position of the red arrow confirming PARP1-DBC1 complex.

FIG. 10 contains 6 panels, Panels (A)-(F), depicting that the PARP1-DBC1 interaction requires the BRCT domain of PARP1. FIG. 10, Panel (A) shows PARP1 and PARP2 structures. Zinc finger regions (ZnI and ZnII) and nuclear localization sequence (NLS) are shown. FIG. 10, Panel (B) shows the effect of deleting the BRCT domain on PARP1-DBC1 complex formation. FIG. 10, Panel (C) shows lack of an endogenous interaction between PARP2 and DBC1. FIG. 10, Panel (D) shows that DBC1 interacts with the PARP1-BRCT domain but not PARP1-CAT. Purified His-tagged recombinant proteins were incubated with Flag-DBC1 cell lysate (0.5 mg) overnight and immunoprecipitated using nickel resin and DBC1 was detected by western blotting. FIG. 10, Panel (E) shows the effect of deleting the BRCT domain on poly(ADP) ribose (PAR) levels. FIG. 10, Panel (F) shows the activity of PARP1 immunoprecipitated from 293T cells, mean±SEM, unpaired two-tailed t-test, **p<0.01.

FIG. 11 shows multiple alignments of Nudix domains from various species. Putative ligand binding residues are indicated by @.

FIG. 12 contains 2 panels, Panels (A)-(B), depicting representative interactions of DBC1-NHD mutants with PARP1 (continued after FIG. 2, Panel (B)). The effects of mutating Y410 or Q420 (Panel (A)), or F535 (Panel (B)) on the PARP1-DBC1 interaction. DBC1 was immunoprecipitated using an anti-V5 antibody agarose beads and probed by western blotting for PARP1. Ratio listed below images was determined from band intensities quantified using Image J.

FIG. 13 contains 5 panels, Panels (A)-(E), depicting that DBC1 specifically binds to NAD⁺, which requires its NHD domain. FIG. 13, Panel (A) shows the biotin-NAD⁺ binding assay. FIG. 13, Panel (B) shows binding of NAD⁺ to DBC1. Each well was loaded with 0.2 mg of a cell lysate from 293T cells stably transfected with empty vector or Flag-DBC1. FIG. 13, Panel (C) shows competition of biotin-NAD⁺ with unlabeled NAD⁺. Flag-DBC1 from cell lysates (0.5 mg) was immobilized in each well and biotin-NAD⁺ (20 μM) was competed off with unlabeled NAD⁺ (0-500 μM). FIG. 13, Panel (D) shows effects of NAD⁺, NADH and NMN on binding of biotin-NAD⁺ to DBC1. Unlabeled NAD⁺, NADH or NMN (200 μM) was competed against biotin-NAD⁺ (20 μM). FIG. 13, Panel (E) shows binding curves of DBC1_(WT), DBC₁₂₄₃₋₉₂₃, DBC1₁₋₅₀₀, and DBC1_(Δ354-396). Kd constants were 22.2, 16.9, 20.6 and 378.7 respectively, determined by GraphPad using “one site, specific binding” formula. Errors are SEM, one-way ANOVA with Sidak's post-hoc correction, *p<0.05, **p<0.01, n.s., not significant.

FIG. 14 contains 6 panels, Panels (A)-(F), depicting that DBC1 inhibits PARP1 activity in the presence and absence of genotoxic stresses. FIG. 14, Panel (A) shows the PAR levels in DBC1 knockout MEFs were determined by western blotting. FIG. 14, Panels (B) to (D) show the effect of DBC1 knockdown in 293T cells on PAR levels under normal conditions and after treatment with (Panel (B)) paraquat (0.5 mM, 24 hr), (Panel (C)) H₂O₂ (0.2 mM, 30 min) or (Panel (D)) etoposide (25 μM, 24 hr). PARG (2 ng) was added into cell lysates to digest PAR for 30 min (*). FIG. 14, Panel (E) shows assessment of DBC1 protein levels in MCF-7 cells knocked down for DBC1 and reconstituted with mutants from FIG. 3, Panel (C). FIG. 14, Panel (F) shows the effect of re-introducing wild-type DBC1 and DBC1-Q391A on PAR levels.

FIG. 15 contains 3 panels, Panels (A)-(C), depicting that DBC1 knockdown protects cells from DNA damage by activating DNA repair. FIG. 15, Panel (A) shows representative images of the comet assay performed on DBC1 knockdown 293T cells after paraquat treatment (0.5 mM, 24 hrs). Images are at 200× magnification. FIG. 15, Panel (B) shows the effect of DBC1 knockdown on survival after paraquat treatment (24 hrs), mean±SEM, unpaired two-tailed t-test, **p<0.01. FIG. 15, Panel (C) shows the effect of knocking down DBC1 on DNA damage response pathways in 293T cells treated with paraquat (0.5 mM, 24 hrs). Western blotting was used to detect phosphor-Chk2 (Thr68), Chk2, phosphor-Chk1 (Ser345), Chk1, phosphor-p53 (Ser15), p53, DBC1. GAPDH served as a loading control.

FIG. 16 shows that NMN reduces DNA damage in primary human fibroblasts. Representative images of the immunofluorescence experiment in FIG. 3, Panel (G). Scale=50 μM. Two fibroblasts cell lines from 94- and 57-year old males (Coriell Institute, #AG08433 and #AG13145) were treated with NMN (500 μM), paraquat (300 μM), or both for 24 hrs at passages 12-13 and immunostained for γH2AX.

FIG. 17 contains 2 panels, Panels (A)-(B), depicting that DNA damage and NAD⁺ levels do not change the interaction of major DNA repair proteins with the PARP1-DBC1 complex. 293T cells overexpressing Flag-DBC1 were treated with (Panel (A)) NMN (0.5 mM) or (Panel (B)) paraquat (0.5 mM) for 24 hrs. Flag-DBC1 was immunoprecipitated and DNA repair proteins were assessed by western blotting as indicated. Both p53 and RAD51 were pulled down with Flag-DBC1 and the interaction did not change with treatment of NMN or paraquat.

FIG. 18 depicts that NMN treatment decreases DNA damage in livers of old mice. Spontaneous DNA damage in the livers of young and old mice treated with PBS or NMN as in FIG. 4E. γH2AX-positive cells were detected by DAB-immunohistochemistry. Foci indicated by red arrows. Young (Y)=6 months, n=4; old (0)=30 months; n=3. Images in upper and lower rows are 100× and 200× magnification, respectively. Scale=50 μM. Insets are representative images shown in FIG. 4, Panel (E).

FIG. 19 contains 2 panels, Panels (A)-(B), showing that PARP1-DBC1 interaction in 6-month old mice is reduced by NMN. Increased relative NAD⁺ levels (n=4/group) (Panel (A)) and reduced PARP1-DBC1 interaction (Panel (B)) in the livers of 6-month old mice treated by daily intraperitoneal injections of PBS (Y-PBS) or NMN (Y-NMN) for one week (500 mg/kg/day), mean±SEM, unpaired two-tailed t-test *p<0.05, ***p<0.001.

FIG. 20 contains 6 panels, Panels (A)-(F), showing that PARP1 activity decreases with age and is reversed by NMN or genetically ablating DBC1. FIG. 20, Panel (A) shows that the enzymatic activity of PARP1 decreases with age. PARP1 was immunoprecipitated from 6-, 22- and 30-month old mouse liver extracts and assayed for maximum activity in the presence of nuclease-treated DNA (n=5 each group, one-way ANOVA with Sidak's post-hoc correction). FIG. 20, Panel (B) shows that PARP1 activation in livers of young and old mice after irradiation. Young (10 month) and old (20 month) mice were exposed to a sub-lethal dose of ionizing radiation (+IR, 7.5Gy). PAR levels are quantified on the right. FIG. 20, Panel (C) shows that the PAR levels are higher in DBC1 knockout mice livers than wild-type at 18-20 months of age. Quantification of PAR is shown on the right. FIG. 20, Panel (D) shows that the PAR levels in 30-month old mouse livers after NMN treatment as in FIG. 4, Panel (C). FIG. 20,Panels (E) and (F) show that the effect of NMN depends on PARP1 activity. The old mice (20 month) were injected intraperitoneally (i.p.) with vehicle (PBS with 10% 2-hydroxypropyl-β-cyclodextrin), NMN (500 mg/kg/d) alone or with PARP1 inhibitor olaparib (100 mg/kg/d) for 7 days. Two hours after the last injection, mice were irradiated with 7.5 Gy and killed 2 hrs later. Equal amounts of liver cell lysates from each group were assayed for PARP1 maximal activity (Panel (E)) and PAR levels by western blot (Panel (F)). Errors are SEM, unpaired two-tailed t-test except (A), *p<0.05, **p<0.01, ^(***)p<0.001, n.s., not significant.

FIG. 21 contains 3 panels, Panels (A)-(C), showing that NMN treatment reduces oxidative DNA damage. FIG. 21, Panel (A) shows PAR levels in 6-, 22- and 30-month-old mouse livers. FIG. 21, Panel (B) shows NAD⁺ levels (n=3 each group) and (Panel (C)) the DNA damage marker 8-OHdG (n=3 or 4) in the livers of 26-month old mice after NMN treatment as in FIG. 4, Panel (C), mean±SEM, unpaired two-tailed t-test, *p<0.05.

FIG. 22 depicts additional blood metrics and body weight measurements in mice treated with NMN. FIG. 22, Panel (A) Experimental design of experiments in FIG. 4, Panel (I). Two groups of 23-month old mice were pretreated with PBS or NMN (i.p. 500 mg/kg/day) for 7 days then exposed to a single dose of ionizing radiation (7.5 Gy). Mice received injections for 2 more days and blood cell counts were conducted on day 7 and 8. (Panel (B)) Continued from FIG. 4, Panel (I): Neutrophils, monocyte, red blood cell and platelet counts. (Panel (C)) Continued from FIG. 4, Panel (J): changes in body weight (n=20/group) and white blood cell, red blood cell and platelet counts. Errors are SEM, Mann-Whitney U-test, n.s., not significant.

FIG. 23 depicts a model for the regulation of PARP1-DBC1 complex during aging. Relatively high NAD⁺ levels in youth maintain optimal PARP1 activity by limiting the PARP1-DBC1 complex, allowing free PARP1 to facilitate DNA repair and promote cell survival. The regulation of PARP1 by NAD⁺ may serve as a negative-feedback loop to limit the consumption of NAD⁺ by PARP1 when levels fall below the threshold of cell viability, thereby allowing other modes of DNA repair to take over until NAD⁺ levels are restored. As NAD⁺ levels decline with aging, PARP1 is increasingly bound to DBC1, resulting in reduced PARP1 and DNA repair activity. Raising NAD⁺ levels liberates PARP1 from DBC1 and restores PARP1 and DNA repair activities.

Note that for every figure containing a histogram, the bars from left to right for each discreet measurement correspond to the figure boxes from top to bottom in the figure legend as indicated.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is based, at least in part, on the discovery that NHDs are NAD⁺ binding domains that regulate protein-protein interactions. As provided herein, the binding of NAD⁺ to the NHD domain of Deleted in Breast Cancer 1 (DBC1) prevents it from inhibiting poly (ADP ribose) polymerase (PARP1), a critical DNA repair protein. As mammals age and NAD⁺ concentrations decline, DBC1 is increasingly bound to PARP1, causing DNA damage to accumulate, a process rapidly reversed by restoring the abundance of NAD⁺. In this way, NAD⁺ may directly regulate protein-protein interactions, the modulation of which may protect against cancer, radiation damage, and aging.

Definitions

As used herein, the following terms and phrases shall have the meanings set forth below. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs.

The singular forms “a,” “an,” and “the” include plural reference unless the context clearly dictates otherwise.

Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. Ranges may be expressed herein as from “about” (or “approximate”) one particular value, and/or to “about” (or “approximate”) another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about” or “approximate” it will be understood that the particular value forms another embodiment. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint. It is also understood that there are a number of values disclosed herein, and that each value is also herein disclosed as “about” that particular value in addition to the value itself. For example, if the value “10” is disclosed, then “about 10” is also disclosed. It is also understood that when a value is disclosed that is “less than or equal to the value” or “greater than or equal to the value” possible ranges between these values are also disclosed, as appropriately understood by the skilled artisan. For example, if the value “10” is disclosed the “less than or equal to 10” as well as “greater than or equal to 10” is also disclosed.

All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. Further, all methods described herein and having more than one step can be performed by more than one person or entity. Thus, a person or an entity can perform step (a) of a method, another person or another entity can perform step (b) of the method, and a yet another person or a yet another entity can perform step (c) of the method, etc. The use of any and all examples, or exemplary language (e. g. “such as”) provided herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed.

Units, prefixes, and symbols are denoted in their Système International de Unites (SI) accepted form. Unless otherwise indicated, nucleic acids are written left to right in 5′ to 3′ orientation; amino acid sequences are written left to right in amino to carboxy orientation.

Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member may be referred to and claimed individually or in any combination with other members of the group or other elements found herein. It is anticipated that one or more members of a group may be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all Markush groups used in the appended claims.

The headings used herein are for organizational purposes only and are not meant to be used to limit the scope of the description or the claims, which can be had by reference to the specification as a whole. Accordingly, the terms defined immediately below are more fully defined by reference to the specification in its entirety.

Illustrations are for the purpose of describing a preferred embodiment of the invention and are not intended to limit the invention thereto.

Unless defined otherwise, all technical and scientific terms used herein have the meaning commonly understood by a person skilled in the art to which this invention belongs. The following references provide one of skill with a general definition of many of the terms used in this invention: Singleton et al., Dictionary of Microbiology and Molecular Biology (2nd ed. 1994); The Cambridge Dictionary of Science and Technology (Walker ed., 1988); The Glossary of Genetics, 5th Ed., R. Rieger et al. (eds.), Springer Verlag (1991); and Hale & Marham, The Harper Collins Dictionary of Biology (1991). As used herein, the following terms have the meanings ascribed to them unless specified otherwise.

As used herein, the term “about” refers to a range of values of plus or minus 10% of a specified value. For example, the phrase “about 200” includes plus or minus 10% of 200, or from 180 to 220, unless clearly contradicted by context.

As used herein, the term “administering” means the actual physical introduction of a composition into or onto (as appropriate) a host or cell. Any and all methods of introducing the composition into the host or cell are contemplated according to the invention; the method is not dependent on any particular means of introduction and is not to be so construed. Means of introduction are well-known to those skilled in the art, and also are exemplified herein.

As used herein, administration “in combination” refers to both simultaneous and sequential administration of two or more compositions. Concurrent or combined administration, as used herein, means that two or more compositions are administered to a subject either (a) simultaneously, or (b) at different times during the course of a common treatment schedule. In the latter case, the two or more compositions are administered sufficiently close in time to achieve the intended effect.

The terms “cancer” or “tumor” or “hyperproliferative disorder” refer to the presence of cells possessing characteristics typical of cancer-causing cells, such as uncontrolled proliferation, immortality, metastatic potential, rapid growth and proliferation rate, and certain characteristic morphological features. Cancer is generally associated with uncontrolled cell growth, invasion of such cells to adjacent tissues, and the spread of such cells to other organs of the body by vascular and lymphatic menas. Cancer invasion occurs when cancer cells intrude on and cross the normal boundaries of adjacent tissue, which can be measured by assaying cancer cell migration, enzymatic destruction of basement membranes by cancer cells, and the like. In some embodiments, a particular stage of cancer is relevant and such stages can include the time period before and/or after angiogenesis, cellular invasion, and/or metastasis. Cancer cells are often in the form of a solid tumor, but such cells may exist alone within an animal, or may be a non-tumorigenic cancer cell, such as a leukemia cell. Cancers include, but are not limited to, B cell cancer, e.g., multiple myeloma, Waldenström's macroglobulinemia, the heavy chain diseases, such as, for example, alpha chain disease, gamma chain disease, and mu chain disease, benign monoclonal gammopathy, and immunocytic amyloidosis, melanomas, breast cancer, lung cancer, bronchus cancer, colorectal cancer, prostate cancer, pancreatic cancer, stomach cancer, ovarian cancer, urinary bladder cancer, brain or central nervous system cancer, peripheral nervous system cancer, esophageal cancer, cervical cancer, uterine or endometrial cancer, cancer of the oral cavity or pharynx, liver cancer, kidney cancer, testicular cancer, biliary tract cancer, small bowel or appendix cancer, salivary gland cancer, thyroid gland cancer, adrenal gland cancer, osteosarcoma, chondrosarcoma, cancer of hematological tissues, and the like. Other non-limiting examples of types of cancers applicable to the methods encompassed by the present invention include human sarcomas and carcinomas, e.g., fibrosarcoma, myxosarcoma, liposarcoma, chondrosarcoma, osteogenic sarcoma, chordoma, angiosarcoma, endotheliosarcoma, lymphangiosarcoma, lymphangioendotheliosarcoma, synovioma, mesothelioma, Ewing's tumor, leiomyosarcoma, rhabdomyosarcoma, colon carcinoma, colorectal cancer, pancreatic cancer, breast cancer, ovarian cancer, prostate cancer, squamous cell carcinoma, basal cell carcinoma, adenocarcinoma, sweat gland carcinoma, sebaceous gland carcinoma, papillary carcinoma, papillary adenocarcinomas, cystadenocarcinoma, medullary carcinoma, bronchogenic carcinoma, renal cell carcinoma, hepatoma, bile duct carcinoma, liver cancer, choriocarcinoma, seminoma, embryonal carcinoma, Wilms' tumor, cervical cancer, bone cancer, brain tumor, testicular cancer, lung carcinoma, small cell lung carcinoma, bladder carcinoma, epithelial carcinoma, glioma, astrocytoma, medulloblastoma, craniopharyngioma, ependymoma, pinealoma, hemangioblastoma, acoustic neuroma, oligodendroglioma, meningioma, melanoma, neuroblastoma, retinoblastoma; leukemias, e.g., acute lymphocytic leukemia and acute myelocytic leukemia (myeloblastic, promyelocytic, myelomonocytic, monocytic and erythroleukemia); chronic leukemia (chronic myelocytic (granulocytic) leukemia and chronic lymphocytic leukemia); and polycythemia vera, lymphoma (Hodgkin's disease and non-Hodgkin's disease), multiple myeloma, Waldenstrom's macroglobulinemia, and heavy chain disease. In some embodiments, the cancer whose phenotype is determined by the method of the present invention is an epithelial cancer such as, but not limited to, bladder cancer, breast cancer, cervical cancer, colon cancer, gynecologic cancers, renal cancer, laryngeal cancer, lung cancer, oral cancer, head and neck cancer, ovarian cancer, pancreatic cancer, prostate cancer, or skin cancer. In other embodiments, the cancer is breast cancer, prostate cancer, lung cancer, or colon cancer. In still other embodiments, the epithelial cancer is non-small-cell lung cancer, nonpapillary renal cell carcinoma, cervical carcinoma, ovarian carcinoma (e.g., serous ovarian carcinoma), or breast carcinoma. The epithelial cancers may be characterized in various other ways including, but not limited to, serous, endometrioid, mucinous, clear cell, brenner, or undifferentiated. In some embodiments, the present invention is used in the treatment, diagnosis, and/or prognosis of melanoma and its subtypes.

As used herein, “DBC1” refers to the protein Deleted in Breast Cancer 1. DBC1 is one of the most abundant, yet enigmatic proteins in mammals (M. Wang et al. Proteomics 15, 3163-3168 (2015); S. M. Armour et al. Mol. Cell. Biochem. 33, 1487-1502 (2013)), with a conserved domain similar to Nudix hydrolases that hydrolyze nucleoside diphosphates but lacking catalytic activity due to the absence of key catalytic residues (V. Anantharaman et al. Cell cycle 7, 1467-1472 (2008); A. S. Mildvan et al. Arch. Biochem. Biophys. 433, 129-143 (2005); J. P. Gagne et al. Nucleic Acids Res. 36, 6959-6976 (2008)). DBC1 may encompass any of the amino acid sequences set forth in GenBank (Accession: Q8N163.2 GI: 85701135); (Accession: O60477.2 GI: 85700960); (Accession: EHH64042.1 GI: 355779566); (Accession: EHH28342.1 GI: 355697794).

As used herein, the term “DNA repair deficiency disorder” refers to a disorder in a subject in which one or more components of the DNA repair pathway(s) is underexpressed, mutated, or less functional than the same component in a wild-type organism. A DNA repair deficiency disorder may refer to a subject in which at least a cell has a mutation. Examples of DNA repair deficiency disorders include, but are not limited to, Ataxia Telangiectasia (A-T), Xeroderma Pigmentosum (XP), Fanconi's Anemia (FA), Li Fraumeni syndrome, Nijmegen breakage syndrome (NB S), A-T-like disorder (ATLD), Werner's syndrome, Bloom's syndrome, Rothmund-Thompson syndrome, Cockayne's syndrome (CS), Trichothiodystrophy, ATR-Seckel syndrome, LIG4 syndrome, Human immunodeficiency with microcephaly, Spinocerebellar ataxia with axonal neuropathy, Ataxia with oculomotor apraxia 1, Ataxia with oculomotor apraxia 2, Diamond Blackfan anemia, Rapadilino syndrome, Turcot Syndrome, Seckle Syndrome, Lynch syndrome, NBS-like syndrome, and RIDDLE Syndrome.

As used herein, “DNA repair proteins” encompass any number of proteins involved in replication, recombination, or homologous recombination. These include, but not limited to, AKT1, BAX, BAG1, ARF1, CDK1/2/4, DAPS, BSG, H-RAS, RAC1, PARP1, S11, and REL. There is also an upregulation of mTOR signaling components AKT, HRAS, R-RAS, MAPK1, RAC1, and RHO A/C/G/J/T2.

As used herein, the terms “effective amount,” “effective dose,” “sufficient amount,” “amount effective to,” “therapeutically effective amount,” or grammatical equivalents thereof mean a dosage sufficient to produce a desired result, to ameliorate, or in some manner, reduce a symptom or stop or reverse progression of a condition and provide either a subjective relief of a symptom(s) or an objectively identifiable improvement as noted by a clinician or other qualified observer. Amelioration of a symptom of a particular condition by administration of a pharmaceutical composition described herein refers to any lessening, whether permanent or temporary, lasting or transit that can be associated with the administration of the pharmaceutical composition. With respect to “effective amount,” “effective dose,” “sufficient amount,” “amount effective to,” or “therapeutically effective amount” of a probiotic microorganism, the dosing range varies with the probiotic microorganism used, the route of administration and the potency of the particular probiotic microorganism.

As used herein, the term “genetic instability” refers to a mutation in a nucleic acid caused by exposure of a subject to radiation, to a carcinogen, to a virus, etc., preferably radiation.

The terms “individual,” “subject,” “host,” and “patient,” used interchangeably herein, refer to a mammal, including, but not limited to, murines, simians, felines, canines, equines, bovines, mammalian farm animals, mammalian sport animals, and mammalian pets and humans. Preferred is a human. More preferred is a human exposed to radiation or a human at risk of being exposed to radiation.

As used herein, the terms “mutation” or “DNA damage,” used interchangeably herein, mean a change in a nucleic acid sequence (in comparison to a wildtype or normal nucleic acid sequence) that alters or eliminates the function of an encoded polypeptide, that alters or eliminates the amount of an encoded polypeptide produced, or that alters or eliminates a regulatory function of the nucleic acid having acquired a mutation. Mutations or DNA damage include, but are not limited to, point mutations, deletions, insertions, inversions, duplications, single-stranded DNA breaks, double-stranded DNA breaks, and DNA lesions as as known in the art.

As used herein, nicotinamide adenine dinucleotide (NAD) and its derivative compounds are known as essential coenzymes in cellular redox reactions in all living organisms. Several lines of evidence have also shown that NAD participates in a number of important signaling pathways in mammalian cells, including poly(ADP-ribosyl)ation in DNA repair (Menissier de Murcia et al., EMBO J., (2003) 22, 2255-2263), mono-ADP-ribosylation in the immune response and G protein-coupled signaling (Corda and Di Girolamo, EMBO J., (2003) 22, 1953-8), and the synthesis of cyclic ADP-ribose and nicotinate adenine dinucleotide phosphate (NAADP) in intracellular calcium signaling (Lee, Annu. Rev. Pharmacol. Toxicol., (2001) 41, 317-345). Recently, it has also been shown that NAD and its derivatives play an important role in transcriptional regulation (Lin and Guarente, Curr. Opin. Cell. Biol., (2003) 15, 241-246). In particular, the discovery of Sir2 NAD-dependent deacetylase activity (e.g., Imai et al., Nature, (2000) 403, 795-800; Landry et al., Biochem. Biophys. Res. Commun., (2000) 278, 685-690; Smith et al., Proc. Natl. Acad. Sci. USA, (2000) 97, 6658-6663) drew attention to this new role of NAD.

The NAD biosynthesis pathways have been characterized in prokaryotes by using Escherichia coli and Salmonella typhimurium (Penfound and Foster, Biosynthesis and recycling of NAD, in Escherichia coli and Salmonella: Cellular and Molecular Biology, p. 721-730, ed. Neidhardt, F. C., 1996, ASM Press: Washington, D.C.) and recently in yeast (Lin and Guarente, Curr. Opin. Cell. Biol., (2003) 15, 241-246; Denu, Trends Biochem. Sci., (2003) 28, 41-48). In prokaryotes and lower eukaryotes, NAD is synthesized by the de novo pathway via quinolinic acid and by the salvage pathway via nicotinic acid (Penfound and Foster, Id.) In yeast, the de novo pathway begins with tryptophan, which is converted to nicotinic acid mononucleotide (NaMN) through six enzymatic steps and one non-enzymatic reaction (Lin and Guarente, Curr. Opin. Cell. Biol., (2003) 15, 241-246). Two genes, BNA1 and QPT1, have been characterized in this pathway in yeast. At the step of NaMN synthesis, the de novo pathway converges with the salvage pathway. The salvage pathway begins with the breakdown of NAD into nicotinamide and O-acetyl-ADP-ribose, which is mainly catalyzed by the Sir2 proteins in yeast. Nicotinamide is then deamidated to nicotinic acid by a nicotinamidase encoded by the PNC1 gene. Nicotinic acid phosphoribosyltransferase (Npt), encoded by the NPT1 gene, converts nicotinic acid to NaMN, which is eventually converted to NAD through the sequential reactions of nicotinamide/nicotinic acid mononucleotide adenylyltransferase (encoded by NMA1 and/or NMA2) and NAD synthetase (encoded by QNS1).

As used herein, “NHD” refers to Nudix homology domain which is conserved in numerous proteins, including but not limited to, DBC1; CCAR2 (KIAA1967_Homo sapiens_24432106); KIAA1967-like (LOC100033113_Monodelphis domestica_334312652; LOC100552552_Anolis carolinensis_327284738); UY3 (UY3_15120_Chelonia mydas_465958204); KIAA1967 homolog (L00564155_Danio_rerio_189524007); CCAR1 (CCAR1_Homo_sapiens_59807829; CCAR1_Monodelphis_domestica_126272572; ccar1_Anolis_carolinensis_327277988; UY3_02172_Chelonia_mydas_465998269; L00568087_Danio_rerio_224495988; LOC101480095_Maylandia zebra_498988520; ccar1_Xenopus_laevis 148229467); LOC575098_Strongylocentrotus purpuratus_390356436; CCAR1-like (LOC100372630_Saccoglossus kowalevskii_291235171); BRAFLDRAFT_124590_Branchiostoma floridae_260814428; CCAR1-like (LOC100741011_Bombus impatiens_350405875); YQE_04229_Dendroctonus ponderosae_478259430; CCAR1 (CpipJ_CPIJ018512_Culex_quinquefasciatus_170068389); CCAR1-like isoform X2 (LOC101456172_Ceratitis capitata_498981650); CCAR1 (KGM_18046_Danaus plexippus_357626416); DAPPUDRAFT_237157_Daphnia pulex_321474758; CCAR1 putative (IscW_ISCW023286_Ixodes scapularis_241836174); LST-3, isoform a (Caenorhabditis elegans_392901726); CBR-LST-3 (Cbr-1st-3_Caenorhabditis briggsae_268535194); SAP domain containing protein (Bm1_48755_Brugia malayi_170592923); LOAG_01502 (LOAG_01502_Loa loa_393911199); P30 dbc protein (Smp_056360.6_Schistosoma mansoni_256081316); CCAR1 (CLF_112465_Clonorchis sinensis_358338740); CCAR1 (CLF_102194_Clonorchis sinensis_358341157); P30 dbc protein (Smp_193440_Schistosoma mansoni_256056754); CCAR1 (CARP-1_Schistosoma japonicum_226484700); GUITHDRAFT_119409_Guillardia theta CCMP2712_428165412; calcium-binding EF-hand domain-containing protein (DFA_02710_Dictyostelium fasciculatum_470268381); development protein DG1124 (DG1124_Dictyostelium discoideum_4731916); RNA-binding region RNP-1 domain-containing protein (cstf2_Polysphondylium pallidum PN500_281210413); DICPUDRAFT_147099_Dictyostelium purpureum_330790620; CHLNCDRAFT_136820_Chlorella variabilis_307105346; VOLCADRAFT_108290_Volvox carteri f. nagariensis_302854449; COCSUDRAFT_49062_Coccomyxa subellipsoidea C-169_384245742; or SELMODRAFT_444593_Selaginella moellendorffii_302797639. Multiple alignments of Nudix homology domains from the various species set forth above are shown in FIG. 11. Representative sequences are set forth below. The amino acid sequence information for the aforementioned proteins are well known in the art and readily available on publicly available databases, such as the National Center for Biotechnology Information (NCBI). For example, exemplary amino acid sequences derived from publicly available sequence databases are provided below in Table 3.

TABLE 3 Nudix homology domain (NHD) proteins (bolded and underlined amino acids denote putative NAD ligand binding residues KIAA1967_Homo_sapiens_24432106 (SEQ ID NO: 1) (264 aa) SDPAYSSKVLLLSSPGLEELYRCCMLFVDDMAEPRETPEHPLKQIKFLLGR K EEEAV LVGGEW SP SLDGLDPQADPQVLVRTAIR C AQA Q TGIDLSGCTKWWRFAEFQ Y LQP GPPRRL Q TVVVYLPDVWTIMPTLEEWEALCQQKAAEAAPPTQEAQGETEPTEQAPD ALEQAADTSRRNAETPEATTQQETDTDLPEAPPPPLEPAVIARPGCVNLSLHGIVEDR RPKERIS F EVMVLAELFLEMLQRDFGYRVYKMLLSLPE LOC100033113_Monodelphis_domestica_334312652 (SEQ ID NO: 2) (266 aa) SDMTYSAKVLLLSSPGLEELYRCCLLFVEDMAEPRESPEHPLKQIKFLLRR K EDEAV MVGGEW SP SLDGPDPKADPQVLVRTAIR C ARA Q TGIDLSNCTKWWRIAEFR Y IQLG PPRRQ R TVVVYLPDIWTLMPSLEEWEALCQQKVAETVAPLQDTVMEAEASVEETNS SELGAAAEASEQDPENPELSLQQEMDPSLPEAPPPPLEPVIIAQPGCTNFSLHALLEDR RPREKIS F EVMVLAALFQEMLQRDFGYKIYKMLLSLPE LOC100552552_Anolis_carolinensis_327284738 (SEQ ID NO: 3) (277 aa) TNSSFSAKVLLLSSPGLEEFYRHCLQYIDDPSDQRESPEHPAKQIKFLLGK K ADETVLI GGEW SP SLDGPDPAANPMVLIRTAIR C TKV Q TGLDLTGCTKWLRFAEFR Y LREGNP SHQ E QTVVFLPDVWSCMPSLEEWEALCKQKAEKNPSAPPQEETAVMEEAEQSSETG LEQETETSEQEAETADPAPEPGVETSPSEPEASSPPLEPAIIASPKPALQGGQPSCTNLS LWTLLEYRRQREKLS F EVAVAAEFFQEMMQRDFGYKLYKALLALPE UY3_15120_Chelonia_mydas_465958204 (SEQ ID NO: 4) (268 aa) ADPAFSAKVMLLSSPGLEELYRHCLLYIEEPSEQKESPEHPTKQIKFLLGR K EDEAVL IGGEW SP SLDGPEPDSDPMVLVRTAIR C TKA Q TGLDLSACTKWFRFAEFR Y LRRGD PLQR E TAVIFLPDVWSCMPSLEEWEALCQQKAEKAPLPSPSPEEKAEMDVEIPEAAP DQEMEANAQEVNATDAAAEPEAPTPPLEPAIVAPPKKPAMQGGQPSCSNLSLCTLLE YRRQREKLS F EVAVMAELFQEMLQRDFGYRLYKALLALPE LOC564155_Danio_rerio_189524007 (SEQ ID NO: 5) (211 aa) TDDAFAVRVLLFSMPCLEDVYSQCCNLSNDGQTQKEAVHPSTLLKFLIVD S GGEQR LPGGHW SP EADGANPAKDSLTLVNTAVR C LKE Q AGLDLSACTQWYKMAELR Y LS GDKV E TVVVLMPDVWNLVPSEEEWASLQLEDDLSLPESPSVVFHPSAGLNLSAVSL SSLLEPQTLQTRDS C EVSLIAEMFSEMLQRDFGLQLYRCLCSLPQ CCAR1_Homo_sapiens_59807829 (SEQ ID NO: 6) (355 aa) ADHLYSAKVMLMASPSMEDLYHKSCALAEDPQELRDGFQHPARLVKFLVGM K GK DEAMAIGGHW SP SLDGPDPEKDPSVLIKTAIR C CKA L TGIDLSVCTQWYRFAEIR Y H RPEETHKGRTVPAHV ET VVLFFPDVWHCLPTRSEWETLSRGYKQQLVEKLQGERKE ADGEQDEEEKDDGEAKEISTPTHWSKLDPKTMKVNDLRKELESRALSSKGLKSQLI ARLTKQLKVEEQKEEQKELEKSEKEEDEDDDRKSEDDKEEEERKRQEEIERQRRER RYILPDEPAIIVHPNWAAKSGKFDCSIMSLSVLLDYRLEDNKEHS F EVSLFAELFNEM LQRDFGVRIYKSLLSLPE CCAR1_Monodelphis_domestica_126272572 (SEQ ID NO: 7) (354 aa) ADHLYSAKVMLMASPSMEDLYHKSCALAEDPQELRDGFQHPARLVKFLVGM K GK DEAMAIGGHW SP SLDGPDPEKDPSVLIKTAIR C CKA L TGIDLSVCTQWYRFAEIR Y H RPEETHKGRTVPAHVETVVLFFPDVWHCLPTRSEWETLSRGYKQQLAEKLQGERKE ADGQDEEEKDDGEAKEISTPTHWSKLDPKTMKVNDLRKELESRALSSKGLKSQLIA RLTKQLKVEEQKEEQKELEKSEKEEEEEEDRKSEDDKEEEERKRQEEMERQRRERR YILPDEPAIIVHPNWAAKSGKFDCSIMSLSVLLDYRLEDNKEHSFEVSLFAELFNEML QRDFGVRIYKSLISLPE ccar1_Anolis_carohnensis_327277988 (SEQ ID NO: 8) (355 aa) TDHLYSAKVMLMASPSMEDLYHKSCALAEDPQEVRDGFQHPARLIKFLVGM K GKD EAMAIGGHW SP SLDGPDPEKDPSVLIKTAIR C CRA L TGIDLSVCTQWYRFAEIR Y HR PEETHKGRTVPAHV E TVVLFFPDVWHCLPTRSEWETLSRGYKQQLAEKLQGERKEA DGEQDEEEKDDGEAKEISTPTHWSKLDPKAMKVNDLRKELESRTLSSKGLKSQLIA RLTKQLKVEEQKEEQKELEKSEKEDEEEEERKSEDDKEEEERKRLEEVERQRRERRY ILPDEPAIIVHPNWAAKSGKFDCSIMSLSVLLDYRLEDNKEHS F EVSLFAELFNEMLQ RDFGVRIYRSLLSLPE UY3_02172_Chelonia_mydas_465998269 (SEQ ID NO: 9) (355 aa) ADHLYSAKVMLMASPSMEDLYHKSCALAEDPQELRDGFQHPARLVKFLVGM K GK DEAMAIGGHW SP SLDGPDPEKDPSVLIKTAIR C CKA L TGIDLSVCTQWYRFAEIR Y H RPEETHKGRTVPAHV E TVVLFFPDVWHCLPTRSEWETLSRGYKQQLVEKLQGERKE ADGEQDEEEKDDGEAKEISTPTHWSKLDPKTMKVNDLRKELESRTLSSKGLKSQLIA RLTKQLKVEEQKEEQKELEKSEKEDEEEEDRKSEDDKEEEERKRQEEMERQRRERR YILPDEPAIIVHPNWAAKSGKFDCSIMSLSVLLDYRLEDNKEHS F EVSLFAELFNEML QRDFGVRIYKALISLPE LOC568087_Danio_rerio_224495988 (SEQ ID NO: 10) (356 aa) ANHTYSAKVMLLANPSLDELYHKSCALSEDPAELRDSFQHPARLIKFLVGM R GKDE AMAIGGHW SP SLDGADPEHDASVLIKTAVR C CKA L TGIDLSLCTQWYRFAEIR Y HR PEETHKGRTVPAHV E TVVLFLPDVWHCLPTRSEWEELSRGLKEQLAEKLLAERKEA DGEQEEEDKDEDDSKEVTTPTHWSKLDPKSMKVSDLRKELESRSLSSKGLKSQLIAR LTKQLKVEEQVEESKEPEKPEPPSVEEDESCRLEDDREEEERKRQEEQERQRRERRY VLPDEPTIIVHPNWAAKNGKFDCSIMSLSVLLDYRLEDNKEHS F EVSLFAELFNEML QRDFGYRIYKALASLPT LOC101480095_Maylandia_zebra_498988520 (SEQ ID NO: 11) (356 aa) ANHTYSAKVMLLANPSIEELYHKSCALAEDPQEVRDSFQHPARLIKFLVGM R GKDE AMAIGGHW SP SLDGADPEKDPSVLIKTAIR C CKA L TGIDLSLCTQWYRFAEIR Y HRP EETHKGRTVPAHV E TVVLFLPDVWHCLPTRSEWEVLSRRLREQLAEKLSAERKEAD GEQEEEEKDDDDSKDVSTPTHWAKLDPKSMKVNDLRRELDCRSLSSKGLKSQLIAR LTKQLKVEEQVEESKEPEKVETKDVEEEEPARTEDDREEEEKKRQEELERQRRERRY ILPDEPTILVHPNWAAKNGKFDCSVMSLSVLLDYRLEDNKEHS F EVSLFAELFNEML QRDFGYRIYKALAALPT ccar1_Xenopus_laevis_148229467 (SEQ ID NO: 12) (355 aa) ADHTYSAKVMLLASPSLEELYHKSCALAEDPIEVREGFQHPARLIKFLVGM K GKDE AMAIGGHW SP SLDGPNPDKDPSVLIRTAVR C CKA L TGIELSLCTQWYRFAEIR Y HRP EETHKGRTVPAHV E TVVLFFPDVWHCLPTRSEWENLCHGYKQQLVDKLQGDRKEA DGEQEEEDKEDGDAKEISTPTHWSKLDPKIMKVNDLRKELESRTLSSKGLKSQLIAR LTKQLRIEEQKEEQKELEKCEKEEEEEEERKSEDDKEEEERKRQEELERQRREKRYM LPDEPAIIVHPNWSAKNGKFDCSIMSLSVLLDYRIEDNKEHS F EVSLFAELFNEMLQR DFGVRIYRELLALPE LOC575098_Strongylocentrotus_purpuratus 390356436 (SEQ ID NO: 13) (401 aa) ANYSYCAKVMLMTSVSQDELYEKCCARAQDSSDIRENFQHPTRLINFLVGQ K GKNE VMAIGGPW SP SLDGADPVNDTSVLIKTAIR T TKA L AGIDLTACTQWYRFLELS Y YRP EEIHKGRVIPARV E TVVIFVPDVWHILPTKVEWESLADLYRKTLSNKLAAVDSRDKK TEDPTPTQEEPAAVKEEEEEEVEEQEHQTPTNWKELDPKNMKVNELRQELEIRGLNS KGLKSQLIARLTKMLKTEQEMEDAEPAAMETDAATENASKEEPKDAPKEEEVSEKD KEKEKKDKEEKEKKDKEDEKKKEIVEEEKKRQREREKRDLESRYTMPDGPVILVHP SPIAKSGKFDCTQQSLSVLLDYRVEDNKEHS F EVFLFAELFNEMLQRDFAFNMYKAI FRAPE LOC100372630_Saccoglossus_kowalevskii_291235171 (SEQ ID NO: 14) (363 aa) ADHLYSAKVMLMASPPLQELYQRSCALAEDPQELKDNFQHPTRLIQFLVGM K GKN EAIAIGGPW SP SIDGENPESDDRVLINTAIR T CRS L TGIDLSSCTHWWRFAEVR Y HRA EEIYKGRLVPARV E TVVIFLPDVWHCLPTRLEWEGLSADYKKQLVDKIAEKHEDVA EQLQEAGTDAVEDDDDFENPTHHKLLDPRNMKVGDLRKELEARGINSKGLKSQLIA RLTKALKTEAESEEQEDIADEDPEEFVEAKTEVEEIEMNSEDKKEEEEKRKQEEKDR LIKEKRHTLPEDPAIIVHPSTTAKGGKFDCSVVSLSVLLDYRMEDNKEHS F EVSLFAE LFNEMLQRDFGFNIYKSLLKIPE BRAFLDRAFT_124590_Branchiostoma_floridae 260814428 (SEQ ID NO: 15) (353 aa) VMLMACPSAEELYHRSCALAEDASDVRETFQHPTRLIQFLVGM K GKNEAVAIGGP W SP SLDGPNPDTDPSVLIKTAIRT T KAL T GIDLKNCTQWYRFAEVR Y HRAAETYKG KTIPERV E TTVMFLPDVHHCLPPRLDWANVSAGYRAQLARKAADEKSEEAGESQEE EEGGEDESGKKAPTHHTELDPKTMKVNELRAELEARGLNSKGLKSQLIARLTKALK MEVEKEEEEKEAKDEAKEEEEEEKEEEVEEDKEKKEEEERKKQEEERERKTRERRY TLPDNPAIIVHPSTTAKGGKFDCAVMSLSVLLDYRVEDNKEHS F EVSLFAELLNEML QRDFAFKIYRALMVAPE LOC100741011_Bombus_impatiens_350405875 (SEQ ID NO: 16) (365 aa) ADYLFSAKVMLISMPAMEEIYKRCCGVSEDRDPDRDYVHPTRLINFLVGL R GKNET MAIGGPW SP SLDGPNPEKDPSVLIRTAVR T CKA L TGIDLSSCTQWYRFLELY Y RRAE TTHKSGRVVPSRV E TVILFLPDVWSCVPTKLEWDGLQLNYKKQLERKLLRAASSPD DLDAANETDEAADDPVPEKKDPTHYSELDPKSMNVNELRQELAARNLNCKGLKSQ LLARLMKTITSEQAKEEGRQDDIDENEKDISPPPKEEEDKKFKDIKDHDEDRRKLCE RERAALEKRYTLPESSHIIVHPSRMAKSGKFDCTVMSLSVLLDYRPEDTKEHS F EVSL FAELFNEMLMRDFGFRIYRALCSLPE YQE_04229_Dendroctonus_ponderosae_478259430 (SEQ ID NO: 17) (339 aa) ADYRFSAKVMLMSVPVIEEIYQKCCAIAEDKDSRDRESEDRDHIHPTRMINFLVGL R GKNETMAIGGPW SP SLDGENPEKDPAVLIKTAIR T CKA L TGIDLSNCTQWYRFVELY Y RRGETTHKGKAIPARV E TVVIFLPDVWSCLPTRLEWEEEEDNEEVLEPTLHSELNP KAMTVVQLRTELKARKLDFKGLKAQLVARLTKALKSEADREEEDPREKPNSDGEA ECEKDDAPEASPSAEKDKKSEPEEKKLDEVQKRRLEKQYTLPDQPHLIVHPSKVAKS GKFDCTSMSLSLLLDYRPEDTKEHS F EVSLFAELFNEMLMRDFGFNIFKALYQVPE CpipJ_CPIJ018512_Culex_quinquefasciatus 170068389 (SEQ ID NO: 18) (509 aa) ADYLYSAKVMLMATPPMAEFYQKCFATAEDRDRYEDLVHPTRLISFLVGIRG K GET MSIGGPW SP SLDGENPQSDPNVLIKTAIR T CKG L TGIDLSNCSRWYRFVELY Y RRSE TYHKGRLIPARI E TVVIFLPDIRSCQPTRPEWDELHLSYKSHLERIINSQSSDSPVPPAV AAAPSTEEPEPAASTVTADSPSPPAAAATAAEPAAAADEESTDKPVDTAPSSTSDIVK PSAEPAEPAAAPKDDTEDDKAADDVVEEEPEVVILDESDEEEPKKEPTPYAQLDVKK LKVPELRTELQARDLPTDGVKNVLVTRLTKALKEEQEEAEKKQAPEAATGEAKSVD KPAADEETPAQEEKKPAEEKSAEKDSADAAAPEDTANPVEKEAEEDFETMDNVDM SEVTVIDEYDSKAEEKTKPEQVKLTEKECQLLEKRYSLPEQPHIIVHPSRTAKSGKFD CAVMSLSVLLDYRQEDSKEHS F EVSLFAELFNEMLTRDFGFNIYKALHMLPA LOC101456172_Ceratitis_capitata_498981650 (SEQ ID NO: 19) (494 aa) ANYLYSAKVMLMACPPIADLYQKCFEDEENENEQHTVHPSRLISFLVGT R GRNEPM AIGGPW SP SLDGENPDKDPAVLIRTAIR T CKA L TGIDLSQCTQWYRFVELQ Y HRQDH KKKDAAARI E TVVIYLPDVHSCMPNATQWQELNQVYKNAVENLIARKSAAAKAAA ATSNTTGGGTEEEGTSSPKAEVGGEGDDATAADTSNADVTKDDANKSVVDEGATA ESGDISTTNGEADADADSAADTSAEVIAIEENDQKEPTHYSKLDLKSMKVREMRDE LEARNLPSKGARHIIMARLAKALNTEKAEDKSSKKATPKSEPAKSEAAKGKPANAK PAKVAEANDKKVEQQKETKKETVEIKEEDIDKSNDEEQEDQEEWNDVDVDMSDIVI LDEYDSSKNPEETPKELNEKEKNQLIRRYKLPTKEHIIVHPNKTAKGGKFDCSIMSLS VLLDYGPADTKERFFEVSIFAELFNEMLMRDFGFNIYKEMYLFKE KGM_18046_Danaus_plexippus_357626416 (SEQ ID NO: 20) (427 aa) ADYRFSAKVMLISMPSLETLYQKCGLTKVDEKDKRTSSKTPLHPTRLIKFLVGQ K GK GGENFAIGGPW SP SLDGEHPETDPGVLVKTAIR T CKA L TGVDLSNCTQWYRVVEFY Y WREGGGRSRL E CVVLFLPDVWSARPSRVEWTTVQDQYKAARDAALRRLLGGESP RRSDDSPDRSPIENLDANASTITIDENDDDDDCKPEATHYSNIDLRTIKVDQLRQELR ARNVSCKGLRSQLVSRLSKLIKAEEEKDTKNEDVMEVVDDEQEDKKDTTDTVEITD DTTNDKEKPVEDKIEKNDANDSKPNDKSKDGESKESDGVSEERKDRPKTEKEIEEEK KRLERERQSLMTRYELPASPHVVVHASGSARAGRFACSVASLSLLLDYRVTDNKEH S F EELFVFAELFNEMLMRDFGFYVYKTLYTLPE DAPPUDRAFT 237157 Daphnia_pulex 321474758 (SEQ ID NO: 21) (320 aa) ADYAYSAKVMLLSLLPMDEFLRKCCPEDEKEDFVHPARLIRFLVGH R GKNETMAIG GPW SP SLDGADPKSDPQVLIRTAIR T CKA L TGIDLSSCTQWYRMAEIR Y HRVSSMKS RI E SVLLFVPDVWSCVPTASQWETIVHSYMQPSSEPMEEETKEETVVDPLKEASHES KLEPKSLKFSELKTELEARNLSSKGMRTQLIPRLTIALKGEAEEEKRKREDAQLNEEE QQQQESSREDSLPADDVDSIHRLDFVASPQILVHPSRTAKAGKFSCSLVSLSVLLDYR LEDTKEHT F EVSLFSELFNEMLMRDFGALVYRSV IscW_ISCW023286_Ixodes_scapularis 241836174 (SEQ ID NO: 22) (355 aa) LDFSFSAKVMLLSAPALEELYQQSCALAEESEEGRLGSMHPARILSFLVGL K GKSET VALGGPW SP SLDGPNPSSDPRVLIRTAVR T CRA L TGIDLSACTQWYRFAEIC Y RRES SSSSCATL E RVVLFFPDVWRCMPTRQEWADLELRLRSISLCGTEDPAGDAPAQALDT LPTTPPLARRCCQLPTHPSEPACALRLQVGDLRTELEARGLLTKGLKSQLVARLAKA LKAEAEQEEEEEEEEVEEEAEEMEEGGEVVDEANEEEEEVEAVEEEAPESEPEEEKP RPTILVYPSRKAKGGRFDCSVMSLSVLLDYRQEDNKEHS F EVSLFAELFNEMLIRDC AFNIYRALLEAPE Caenorhabditis_elegans_392901726 (SEQ ID NO: 23) (442 aa) ADHRHQVKVLLLSHAGKSEVVKKAFCLMADGTTDDHQEPQSLLKNLHFLVGA R G KETMGIGGSW SP SQDGADPNSATTMIRTAVR T TKS L TGIDLSSVSQWFSMVQIR Y Y RADKQRI D HVNYLLPDTQSLALDDAQWMLAETKIAEQLKAKLANVDALKIEEDEPP VVMMVEESESVVAAAAAAADVVPEQSIPDVKKEEELQAEEPKVLDNVKAEESDVV ADVSMNSTTDADNSEAPAAENGQGPTNWSNLDPKSMKVAELRVELELRGLETKGI KTLLVQRLQTALDTEKAAEASVAARDVEMRDAAENAVKQEGGEENPAAFIAPSIEE TKAKTEAEAKKEAEEAEKRKKKEEQLEKEKKEKREALEKHYQLPKDKKILVFPSKS FKSGKFDCKVLSLSSLLDYRHDDNKENQ F EVSLFAEAFKEMIERNAAFTIYETL Cbr-lst-3_Caenorhabditis_briggsae_268535194 (SEQ ID NO: 24) (436 aa) ADHRHQVKVLLLSHAGKTEVVKKSFCLMADGTTDDHQEPQSLLKNLHFLVGA R GK ETMGIGGSW SP SLDGADPTSTTTMIRTAVR T TRA L TGIDLSSVSQWFSMVQIR Y YRA DKQRI D HVNFLLPDTQSLALDDATWSSAEASIGEQLKAKLAEVDALKIEEEPEVVEM VEAVEPAAEVVVTPEAAVVTAETVAAPEDAPSDVKESIVLLYMVENENDVSMNSET GEADKPIVAGQGPTNWSKLDPKSMKVAELRVELELRGLETKGIKTLLVQRLQTALD SEKSTEAAASKDVEMKDVKDEVKQEAGAVAGEENPAAFIAPPIEETKAKTEAEAKK EQEEADKKKKKEEQLEKEKKDKRDALEKHYQLPKDKKVLVFPSKTFKSGKFDCKV LSLSSLLDYRHDDNKESQ F EVSLFAEAFKEMIERNSAFTIYETL Bm1_48755_Brugia_malayi_170592923 (SEQ ID NO: 25) (398 aa) ADCRFSVKIVLMSHQGLSLVHQKAFGLLVDGSIDENVDSVSLKRCLNFVVGT R NKE NIMAIGGAW SP SLDGDNPETDPQVFVRTAIR T VRA L IGVDLSRCPRWYKMAEIR Y YR AEKDRM D TCCLFLPDTSGLMPTEDCYQQLLATLKDQLGNKLAAVDAQKLVLPSTV AVTATDCGDAGEGATVTTEPMAPAGDTQQQLQQGQQQSDVNKEQVQEVEEEDDE DLNPTHWSKLDIRTMKVAELRQELMARDLETKGVKSVLCARLQEALDQEKTKDED KEDVCLKTAVGMIEVAKPQEENEEKELTDEDKKAVEKFEKEKKEKKASLERHFTIP KEPGILVYPNRMAKGGKFDCKIVSLHTMLDYRIEDNKEHS F ELAVMAECISEMLDR SQAFIAYKTL LOAG_01502_Loa_loa_393911199 (SEQ ID NO: 26) (391 aa) ADYRFSVKVVLMSHQGLSLVHQKAFGLQVDGSIDENIDPASLKRCINFVVGT R NKE MMAIGGAW SP SLDGDNPESDPQVFVRTAVR T VRA L IGVDLSKCPRWYKMAEIR Y Y RAEKDRM D TCCLFLPDTSGLMPTEDCYQQLLATLKDQLGNKLAALDAQKLVLPST VAALATDSGDAGEGTTTTTEPVAQAGDTQQQLQQGQQQIDANKEQVQEVEEDDDE DLNPTHWSKLDIRTMKVAELRQELMARDLETKGVKSVLCARLQEALDHEKTKDED KGDKAEVAKVKEEEKEEKELTDEDKKAIEKFEKEKKEKKASLERHFTIPKELGILVH PNRMAKGGKFDCKIVSLHTMLDYRTEDNKEHS F ELAVMAECISEMLDRSQAFVAY KTL Smp_056360.6_Schistosoma_mansoni 256081316 (SEQ ID NO: 27) (377 aa) ADYSYSARVMLMACPQLGELYKNTCRMADDANGAGKVLPDKSIHFLVGG R AKSE TMALGGPW SP SLDGPDPQGNPMTLIKTAIR T FKG L TGLDLSSCTEWVRFMELK Y YR MPDTKAPAFTEAEEEREITSERP E VVVFFIPNAAHLIPSEEQWAKTKEYYNSILQKQL TVEKVEDESMVEQQDGDMSVADVSVEEPEESIARSDIEPTHYSKLDVNTLKVSDLR NELAARKLDTKGLKVNLVARLQSALDEEKKADAPEDIKIDEEIKAEQTPNKISSPSAT QPKDDSKDLSEKDRRRLERLYRLGDKPAIVIHPNKSAKGGRFDCHRVSLFSLLDYHT EDQKEHN F EVSLFAEQFHEMLQRDAAFTIFKAIHDAPE CLF_112465_Clonorchis_sinensis_358338740 (SEQ ID NO: 28) (378 aa) ADYSYSARVMLMACPQLAELYKNTCHMADDVSGTDKVPPGKNIHFLVGG R AKSET MAIGGPW SP SMDGADPCGDPRTLINTAIR T FKG Y TGLDLSSCTEWIRFMEIR Y YRFA DTKAPAFTGDDEERLVTTERP E VVVFFIPNASHLIPSDEEWAKVKEHYTSVLQALLS PEQKPEVEATPGADATEVETSVVDASMDDGDEAGTRSDMEPTHYSKLDANSLKVN ELRNELAARNLDTKGLKVNLVARLQAALDEEKKADTPEETKAAEDSKAEETPAKA TTPTQSKDESKDLSEKERRRLERLYRLNDKPAIIIHPNKSARGGRFDCHRVSLFSLLD YRTEEQKEQN F EVSLFAEQFHEMLQRDCAFTIFKAINDAPE CLF_102194_Clonorchis_sinensis_358341157 (SEQ ID NO: 29) (436 aa) AETGFYVNVLLLSMPSIPTLQDKTTVRAESSDREKVPLRKYIKILALS K TNERFKAIG GPW NP DLDGQDPVGDSRALINAAIR I CKE Q LGLDLSYCTQWHRFLEFR Y SRTEGST ARPASVLFPGSQLWGRSFPESANSKSATPSKPYH R IVVYFLPDIWSLMPSTGDWANV KRSMENALSRKLPQLFPMSQAEINALSDATSTGASSDDAKNKSNPTTCPTGVTATAL GDTATTSTAGDSQNNPTAAPKPDQSDSMLDTSAREIGDEGLQSPTRASGGDKNDSS QEVSELREQLKVRNLPADGIKAQLLSRLKTAVEKEAEQARKEEEERKKKEKEMQEA LAAKEEEDKKRESSKPTIEISATPKADACIALRNYPSIIVQKRLTDDYTLQTVSLDSVL ESKSDFMDARS Y ELVICVHNLFDMVRRDFIFTLFRAL Smp_193440_Schistosoma_mansoni_256056754 (SEQ ID NO: 30) (466 aa) NDSGFAAYVLLLSLPAMAELMEKIVVRAESPSRMRGSLRKYIKILAAG K VDERLKAI GGSW SR DLDGPDPATNPQTLVNTAIR V CKQ L IGLDLSYCTQWHRFLEFR Y SRTEGST AQPTSVLFPGSQLWGRPVTESPESDMIPPSKPFH Q IVVYFIPNVWSLMPTDEEWSTIK LAYENILASKEPKVFPMSPSNLKKFSGLESASKGTGDGKLNVVSELDSNLLKSPTQD NAHEDSNVSKMDEGNKSTVQAPVEFHRSSPYLAGQETVPKVAAISETEDGFESVDL AAQGNPNQEGTDKCQKKLHTELNLASMKVSELREQLKARNLPTEGVRAQLLTRLK TAIQEEEEKESAKKAEKEKMEQEKTLQSVTIDKSPQVSEEQIKPLNTESGSKSWTDAP KLTLRDLPSIIVLRKKTVDFTVQSVGLDVVMDSKSDFMDCRS Y EFMFCIHTIFDMLR RDSVFTLFRAL CARP-1_Schistosoma_japonicum_226484700 (SEQ ID NO: 31) (467 aa) SDSGFAAYVLLLSLPAMAELMEKIVVRAESPSRVRGSLRKYIKILAVG K VDERLKAI GGSW NP DLDGSDPATNPQTLINTAIR N CK Q LIGLDLSYCTQWHRFLEFR Y SRTEGST AQPTSVLFPGSQLWGRPATESNDVIPPSKPFH Q IVVYFIPNVWSLMPADEEWSTIKLA YENVLASKEPNVFPLAPSSLKKFSGLESASKETSDGKLKLVVEMDSNSLKSPAQDNL CEDPNASKMDEGNKSILQAPVEHDGSALSTADQESVSKIANTPEAEDGFESMGPKNI SIQGNPNQEGTEKCQKKLHTEINLANIVIKVSELREQLKARNLPTEGVRAQLLTRLKM AIQEEEEKESAIKAEKEKMEQAKALQLVTIDKSPQVPEEQVKPVNAESGSKLKTDVP KLALRDLPSIIILRKKNADFTVQSVGLDVVMDSKSDFMDSRS Y EFMFCIHTIFDMLRR DSVFTLFRAL GUITHDRAFT_119409_Guillardia_theta_CCMP2712_428165412 (SEQ ID NO: 32) (372 aa) FTVKYNAKVMLLQGLPDLWWEAGGTSKAHLGKMIKFLCVK S QKHGLFCMGGMW ME EKDGGGSTGPDTEALIRTAIR C VKE T IDVDLSGVKKWHRFMEIQ Y NRPAEMYK GQWYPEQE E HTIIFLPELEGAMPDREQFTSSISNLEDELNSKAHAAWEKDMEERRRA AKEAEIKRAAAAAAAAEAAKLAAAAAAAAAAAKAAEAEAAAAESISTGDRKTPAG AGNINEAGQPGDGKSAEVKLESVVPATSSGVQQDADASGQLATSTGEVKTEQEGG GGHGVKEEVKGPPPPEPIKLDFPEEPCILVRPKWEEGGDGKGQIKASLISLDGLLDYN LDDVLEKN F EVSLFAEFFHEMLEHMFASRILKDIQDRAR DFA_02710_Dictyostelium_fasciculatum 470268381 (SEQ ID NO: 33) (286 aa) NGVKYNAKVMLFQQLPVDSTTPTNLCKRLKFLVAK E NKDICCIGGTW SP SLDGQDI DNPQTLINTAIR T TKE Y TQFDLSKCVKWIKFMEVH Y YRPPTEKNQQYQ E VTVIFVPD ISNITPNEINHSLLQQDKPSEKEEGEDDHHQQQQQQQQQQQQQQQEEGTNEYDPEN QGEDKQDSSNDPAQTDAKISITSETSSERKTTSPNPAPLVALPKELQSCFIITTPLSDTS SIKYRAMMLSLDGLLDYEESDKFEGT F EASLFGELFYLMLATEMGNIVMQALLDFT P DG1124_Dictyostelium_discoideum_4731916 (SEQ ID NO: 34) (287 aa) THIKYNSKVMLYSFYSNIEDPSITKKIKFLVSK E DKDISCIGGTW LP DLDGEDVNDHP QTLINTAIR T TKE Y TQIDLSGCKKWYKFMEVH Y YRPPTEEQSYYQ E ITVIYVPDITDI QPMDVDSLLKVPTVSETTPSAPVGVTTATTKTTEEEEEEDQAPKDHVSKDFDND- ETSSNTEQNQPPKSSTTSNTTKPAAAVPTTTAATATTTHGSLHLPKASKFYNVITPSS EGNRYKAMMLSLDGLLDYDESDTHEGT F EASLFSELFYLMLCRDMGTNILTSIVNY RP cstf2_Polysphondylium_fiallidum_PN500_281210413 (SEQ ID NO: 35) (316 aa) DNIKYNAKVMMFQQVTPVNQTAPLHINKRLKFLVAK E NKDISCIGGSW NP TLDGN DINDPQTLINTAIR T TKE Y TQIDLSRCNRWVKFMEIH Y YRPPTEAMAQFQ E ITVIFVP DLTNITPFDGKEHMKNKVTTASPTEKSTESNNEHHEETDDGEENHPPAGNDTGDSE KPAASDEIVGEVTGEPKDKDEMEMAPSSSVSASSNDQESHHHNQTSGGIQSPNSSSS QSVSASTATAISTAANGSDDSHSCFSVTTPKSENMKYRSMMLSLDGLLEYDESDKFE GT F EASLFGELFYLMLCRDFGSLILQSILYFNP DICPUDRAFT_147099_Dictyostelium_purpureum_330790620 (SEQ ID NO: 36) (222 aa) NCIKYNAKVMLYSYYSNSEDPSISKRLKFLVAK E DKDISCIGGSW NP ELDGEDINDP QTLINTAIR T TKE Y TQIDLSSVKKWVKFMEVH Y YRPPTDEFSFYQ E ITVVYIPNISEIP PLDVETLMKNNSKGLETDKQGEEQSTITPNTILPHNSKKFYTVTTPSSDGNKFKAMM LSLDGLLDYDETDVHEST F EASLFSELFYLMLARDMGTTILNTIINYRT CHLNCDRAFT_136820_Chlorella_variabilis_307105346 (SEQ ID NO: 37) (293 aa) GSVVYNAKVMFTTGLGEGEVAALLAGAADKAGDHLCRLLKFVVAR A DRNGDKSG IFCLGGRC DP AMDGDPTQGDAALVAAARR H VAA Q ARLELPPAGAGAWLRFIEVH Y TRLDRNDVEHHQ E VTVVFMVDASRCLPSAADWPHVWQQQQKPVLLQKLAAERAA KQEAAAAKEPKPAAAGGLKEGGEEGERKEGGEEGEKEGEVAAARAVEEQEEEEAL PEPEMPARPQLQLVGLHTDKLRLKTAAVSLDGLLDYNTSDKDECT F ELSLFAEAFHE ALMRDAGCTILAELYRQR VOLCADRAFT_108290_Volvox_carteri_f._nagariensis_302854449 (SEQ ID NO: 38) (365 aa) GSLTLGGQVLLVQGLSPSLRMDVLVGPHHEGGAHLVHALKFVAAR F SRSQPSAGAE EREGKDKEGGKDRQRGVLGALGGTW DP ELDGGDPESEDGGLIRTCIR H VKN Q AGV DLSACAHWLRVCDIT Y MRAASSPTSGSGDAASAGQLSSSISDPQLREVVVVFAAVP DACMAGPDAWPEEARQQQAFKQQRIALESEARKKEDAATARKDKDVVTEKEKTK DEKRDKREEETNPGAEASKDKDVDDPLKGAGKDKDKDSNDNNKEADGDSSKAEPE AAPVREVPLPEEPGIQLRGRASGLTAGAGLGGYERIKTFSISLHGLLDYDETDRDEPT F ELSVFTECFQDMLSREYGGTIYAALVAERS COCSUDRAFT_49062_Coccomyxa_subellipsoidea_C-169_384245742 (SEQ ID NO: 39) (326 aa) GAVKWNARVVLLSGLDDDARKELLKGVHHGGQHLHQLLKFLTVR T ETDKDDGRV ERSGITAIGGQH DP SLDGPITDASKSTEPLIATCVR H AKK L LGVDLSACKEWLPVIEV H Y QRPPSSLSPDATEST E ITVIFLAIARRVMPEDWQSTWKEQEAWLKGKAAREEAVT KKEEEEKASKAKAVEEKAKPEEATKAEGAAVKDDEPAGAEKPAKRAKTGDVEEEK KKDHGKVVDTDIKDADNKAPEAPQEAETDAKVPEVPRLLFRGKRSAKERWRSASIS LDGLLDYDEEDRDEST M ELSLFAEGFQEMLARDYGERILKSLYAER SELMODRAFT_444593_Selaginella_moellendortiii_302797639 (SEQ ID NO: 40) (287 aa) GSTVWNVKVMLMSGLTEEYVADLLSDKPSDKPTSFQKMLKFVALR K DRNAIMAA GTRW DK SLDGGDPTVDDSGLIRAAVR S LKE L IQLDLSECKDWFRFAEVH Y ERVDED GFPSHR E ISVIFFPDMSSCVPSFENWCLQWNQRKQAKLEREGQSKKEVKPSEKKDA AEKESISEGTPETDVNNGEPVAAKEEEKKEKEEKKEKDPPKDSEVKKDEAPEHPGFL LMTKRTKASKLRSMTISLDGLLDYDENDKDECT F ELSLFAEAFAEMIQFRKGSQILA SLENLRR

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 1 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underlined text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 52, 64, 65, 86, 90, 109, 119, and/or 234, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 2 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 52, 64, 65, 86, 90, 109, 119, and/or 236, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 3 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 52, 64, 65, 86, 90, 109, 119, and/or 247, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 4 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 52, 64, 65, 86, 90, 109, 119, and/or 238, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 5 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 51, 63, 64, 85, 89, 108, 115, and/or 181, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 6 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 52, 65, 66, 87, 91, 110, 127, and/or 325, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 7 are preferably conserved for function and remaining positions can be modified. Positions believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 52, 65, 66, 87, 91, 110, 127, and/or 325, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 8 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 52, 65, 66, 87, 91, 110, 127, and/or 325, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 9 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 52, 65, 66, 87, 91, 110, 127, and/or 325, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 10 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 52, 65, 66, 87, 91, 110, 127, and/or 326, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 11 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 52, 65, 66, 87, 91, 110, 127, and/or 326, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 12 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 52, 65, 66, 87, 91, 110, 127, and/or 325, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 13 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 52, 65, 66, 87, 91, 110, 127, and/or 371, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 14 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 52, 65, 66, 87, 91, 110, 127, and/or 333, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 15 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 44, 57, 58, 80, 84, 102, 119, and/or 323, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 16 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 51, 64, 65, 86, 90, 109, 127, and/or 335, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 17 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 57, 70, 71, 92, 96, 115, 132, and/or 309, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 18 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 51, 64, 65, 86, 90, 109, 126, and/or 479, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 19 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 50, 63, 64, 85, 89, 108, 123, and/or 464, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 20 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 55, 69, 70, 91, 95, 114, 125, and/or 397, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 21 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 47, 60, 61, 82, 86, 105, 116, and/or 295, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 22 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 52, 65, 66, 87, 91, 110, 123, and/or 325, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 23 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 53, 65, 66, 86, 90, 109, 118, and/or 417, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 24 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 53, 65, 66, 86, 90, 109, 118, and/or 411, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 25 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 53, 65, 66, 87, 91, 110, 119, and/or 373, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 26 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 53, 65, 66, 87, 91, 110, 119, and/or 366, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 27 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 50, 63, 64, 85, 89, 108, 134, and/or 347, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 28 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 50, 63, 64, 85, 89, 108, 134, and/or 348, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 29 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 49, 62, 63, 84, 89, 107, 149, and/or 411, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 30 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 49, 62, 63, 84, 89, 107, 149, and/or 441, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 31 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 49, 62, 63, 84, 89, 107, 147, and/or 442, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 32 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 41, 54, 55, 77, 81, 100, 117, and/or 342, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 33 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 36, 48, 49, 69, 73, 92, 105, and/or 256, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 34 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 34, 46, 47, 68, 72, 91, 104, and/or 257, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 35 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 37, 49, 50, 70, 74, 93, 106, and/or 286, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 36 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 34, 46, 47, 67, 71, 90, 103, and/or 192, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 37 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 46, 63, 64, 84, 88, 109, 122, and/or 264, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 38 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 46, 82, 83, 104, 108, 127, 157, and/or 335, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 39 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 45, 67, 68, 72, 76, 114, 130, and/or 297, or any combination thereof.

In some embodiments, the following amino positions and/or residues of SEQ ID NO: 40 are preferably conserved for function and remaining positions can be modified. Positions (indicated in bolded-underline text in Table 3 and @ in FIG. 11) believed to be involved in putative ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues: 46, 59, 60, 81, 85, 104, 117, and/or 27, or any combination thereof.

Included in Table 3 are variations of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or more amino acids on the 5′ end, on the 3′ end, or on both the 5′ and 3′ ends, of the domain sequences as long as the sequence variations maintain the recited function and/or homology Included in Table 3 are polypeptide molecules comprising, consisting essentially of, or consisting of: 1) an amino acid sequence having at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 99.5%, or more identity across their full length with a nucleic acid sequence of SEQ ID NO: 1-40, or a biologically active fragment thereof; 2) an amino acid sequence having at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 99.5%, or more identity across their full length with a nucleic acid sequence of SEQ ID NO: 1-40, or a biologically active fragment thereof, comprising at least one or more (e.g., one, two, three, four, five, six, seven, eight, nine or ten) conserved ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues set forth in Table 3; 3) an amino acid sequence having at least 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200, 205, 210, 215, 220, 225, 230, 235, 240, 245, 250, 255, 260, 265, 270, 275, 280, 285, 290, 295, 300, 305, 310, 315, 320, 325, 330, 335, 340, 345, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1050, 1100, 1150, 1200, 1250, 1300, 1350, 1400, 1450, 1500, 1550, 1600, 1650, 1700, 1750, 1800, 1850, 1900, 1950, 2000, 2050, 2100, 2150, 2200, 2250, 2300, 2350, 2400, 2450, 2500, 2550, 2600, 2650, 2700, 2750, 2800, 2850, 2900, 2950, 3000, 3500, 4000, 4500, 5000, 5500, 6000, 6500, 7000, 7500, 8000, 8500, 9000, 9500, 10000, or more amino acids, or any range in between, inclusive such as between 200 and 600 amino acids; 4) an amino acid sequence having at least 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200, 205, 210, 215, 220, 225, 230, 235, 240, 245, 250, 255, 260, 265, 270, 275, 280, 285, 290, 295, 300, 305, 310, 315, 320, 325, 330, 335, 340, 345, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1050, 1100, 1150, 1200, 1250, 1300, 1350, 1400, 1450, 1500, 1550, 1600, 1650, 1700, 1750, 1800, 1850, 1900, 1950, 2000, 2050, 2100, 2150, 2200, 2250, 2300, 2350, 2400, 2450, 2500, 2550, 2600, 2650, 2700, 2750, 2800, 2850, 2900, 2950, 3000, 3500, 4000, 4500, 5000, 5500, 6000, 6500, 7000, 7500, 8000, 8500, 9000, 9500, 10000, or more amino acids, or any range in between, inclusive such as between 200 and 600 amino acids, comprising at least one or more (e.g., one, two, three, four, five, six, seven, eight, nine or ten) conserved ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues set forth in Table 3; 5) a biologically active fragment of an amino acid sequence of SEQ ID NO: 1-40 having at least 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200, 205, 210, 215, 220, 225, 230, 235, 240, 245, 250, 255, 260, 265, 270, 275, 280, 285, 290, 295, 300, 305, 310, 315, 320, 325, 330, 335, 340, 345, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1050, 1100, 1150, 1200, 1250, 1300, 1350, 1400, 1450, 1500, 1550, 1600, 1650, 1700, 1750, 1800, 1850, 1900, 1950, 2000, 2050, 2100, 2150, 2200, 2250, 2300, 2350, 2400, 2450, 2500, 2550, 2600, 2625, or more amino acids, or any range in between, inclusive such as between 200 and 600 amino acids; or 6) a biologically active fragment of an amino acid sequence of SEQ ID NO: 1-40 having at least 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200, 205, 210, 215, 220, 225, 230, 235, 240, 245, 250, 255, 260, 265, 270, 275, 280, 285, 290, 295, 300, 305, 310, 315, 320, 325, 330, 335, 340, 345, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1050, 1100, 1150, 1200, 1250, 1300, 1350, 1400, 1450, 1500, 1550, 1600, 1650, 1700, 1750, 1800, 1850, 1900, 1950, 2000, 2050, 2100, 2150, 2200, 2250, 2300, 2350, 2400, 2450, 2500, 2550, 2600, 2625, or more amino acids, or any range in between, inclusive such as between 200 and 600 amino acids, comprising at least one or more (e.g., one, two, three, four, five, six, seven, eight, nine or ten) conserved ligand (e.g., NAD or NAD analogs or derivatives thereof described infra) binding residues set forth in Table 3.

As used herein, the term “radiation” refers to energy which may be selectively applied, including energy having a wavelength of between 10⁻¹⁴ and 10⁴ meters including, for example, electron beam radiation, gamma radiation, x-ray radiation, light such as ultra-violet light, visible light, and infrared light, microwave radiation, cosmic or galactic radiation, and radio waves. The radiation is in particular an ionizing radiation which comprises subatomic particles and/or ions or electromagnetic waves which are energetic enough to ionize atoms or molecules. “Irradiation” refers to the application (exposure) of radiation to a subject, e.g., in radiation oncology for the treatment of cancer and/or during accidental or environmental radiation.

As used herein, the term “radiation-induced toxicity” or grammatical equivalents thereof means any damage to a cell, tissue, or any of its components, such as a nucleic acid (DNA or RNA), caused by radiation (e.g., as caused from X-ray exposure (during medical or dental visits), nuclear spills, nuclear clean-up).

As used herein, the term “radiation treatment” means a procedure including, but not limited to, radiotherapy, radiosurgery (i.e., radiation surgery) and/or any other (in particular) medical procedure, which uses ionizing radiation and in which a subject is treated by applying radiation to the subject's body. The radiation used for the treatment (the “treatment radiation”) is effective for a particular part(s) of the body. Radiation treatment comprises a step of providing an energy value which depends on the radiation energy, in particular the energy of the treatment radiation, which is applied to the patient's body, and a step of controlling the period of time over which radiation treatment is performed in accordance with the energy value. The ionizing radiation can be emitted by an irradiation device such as an x-ray tube and/or a particle accelerator and/or an antenna and/or a radioactive material.

As used herein, the term “substantially decreased” and grammatical equivalents thereof refer to a level, amount, concentration of a parameter, such as a chemical compound, a metabolite, a nucleic acid, a polypeptide, a physical parameter (pH, temperature, viscosity, etc.), or a microorganism measured in a sample that has a decrease of at least 10%, preferably about 20%, more preferable about 40%, even more preferable about 50% and still more preferably a decrease of more than 75% when compared to the level, amount, or concentration of the same chemical compound, nucleic acid, polypeptide, physical parameter, or microorganism in a control sample. In some embodiments, the parameter is not detectable in a subject sample, while it is detectable in a control sample.

As used herein, the term “substantially increased” and grammatical equivalents thereof refer to a level, amount, concentration of a parameter, such as a chemical compound, a metabolite, a nucleic acid, a polypeptide, a physical parameter (pH, temperature, viscosity, etc.), or a microorganism measured in a sample that has an increase of at least 30%, preferably about 50%, more preferable about 75%, and still more preferably an increase of more than 100% when compared to the level, amount, or concentration of the same chemical compound, nucleic acid, polypeptide, physical parameter, or microorganism in a control sample. In some embodiments, the parameter is detectable in a subject sample, while it is not detectable in a control sample.

As used herein, the terms “treat,” “treating,” and “treatment” include: (1) preventing a pathological condition, disorder, or disease, i.e. causing the clinical symptoms of the pathological condition, disorder, or disease not to develop in a subject that may be predisposed to the pathological condition, disorder, or disease but does not yet experience any symptoms of the pathological condition, disorder, or disease; (2) inhibiting the pathological condition, disorder, or disease, i.e. arresting or reducing the development of the pathological condition, disorder, or disease or its clinical symptoms; or (3) relieving the pathological condition, disorder, or disease, i.e. causing regression of the pathological condition, disorder, or disease or its clinical symptoms. These terms encompass also prophylaxis, therapy and cure. Treatment means any manner in which the symptoms of a pathological condition, disorder, or disease are ameliorated or otherwise beneficially altered. Preferably, the subject in need of such treatment is a mammal, more preferable a human.

A “variant” or “biologically active fragment” of a polypeptide refers to a polypeptide having the amino acid sequence of the polypeptide in which is altered in one or more amino acid residues. The variant may have “conservative” changes, wherein a substituted amino acid has similar structural or chemical properties (e.g., replacement of leucine with isoleucine). A variant may have “nonconservative” changes (e.g., replacement of glycine with tryptophan). Analogous minor variations may also include amino acid deletions or insertions, or both. Guidance in determining which amino acid residues may be substituted, inserted, or deleted without abolishing biological or immunological activity may be found using computer programs well known in the art, for example, LASERGENE software (DNASTAR).

The term “variant,” when used in the context of a polynucleotide sequence, may encompass a polynucleotide sequence related to that of a particular gene or the coding sequence thereof. This definition may also include, for example, “allelic,” “splice,” “species,” or “polymorphic” variants. A splice variant may have significant identity to a reference molecule, but will generally have a greater or lesser number of polynucleotides due to alternate splicing of exons during mRNA processing. The corresponding polypeptide may possess additional functional domains or an absence of domains. Species variants are polynucleotide sequences that vary from one species to another. The resulting polypeptides generally will have significant amino acid identity relative to each other. A polymorphic variantion is a variation in the polynucleotide sequence of a particular gene between individuals of a given species. Polymorphic variants also may encompass “single nucleotide polymorphisms” (SNPs) in which the polynucleotide sequence varies by one base. The presence of SNPs may be indicative of, for example, a certain population, a disease state, or a propensity for a disease state.

1. Anti-NHD Antibodies

In certain embodiments, the present invention relates to antibodies and antigen binding fragments thereof that bind specifically to NHD and uses thereof. In some embodiments, the antibodies bind to a domain of NHD required for complex formation with c-Myc. Accordingly, in certain embodiments the antibodies described herein are able to inhibit complex formation between NHD (e.g., DBC1 or Table 3 proteins) and any of the proteins set forth in Table 4.

Table 4: NHD-domain containing protein (e.g., DBC1) interactors (see FIGS. 4 and 5 of Giguère, S et al. Mol Cell Proteomics (2016) 15(3): 791-809) PARP1, HNRPLL, SON, SUGP2, WDR33, THOC5, PUS1, SYMPK, THOC2, SART3, LSM4, PLRG1, SF3B2, SNRNP40, XAB2, ZCCHC8, PRPF8, PRPF4, POLR3B, POLR1A, POLR2D, POLR2A, SUPT5H, SUPT6H, GT3C4, EXOSC7, EIF4H, GTF3C5, MRPS23, SEP15, FKBP5, MRPS34, TPX2, TRIM27, USP7, UBE2K, STAG2, PDS5B, SMC4, PDS5A, NCAPG2, AKAP8, NUMA1, CEP170, POGZ, CTR9, TBLXR1, G3BP1, TLE1, SPIN1, COPS3, TLE3, GPS1, CSNK2A1, PRKDC, MSH3, MSH6, POLA1, TMPO, FEN1, PRIM2, CHTF18, AKAP8L, MLF2, SPATA5, ZMPSTE24, SMARCA2, SIRT1, SMARCA4, ARID1A, SMARCC2, KDM3B, ADNP, HDAC3, VPRBP, LCP1, KPNA3, TOMM40, IPO9, TIMM13, COBRA1, SAFB2, PELP1, TCEB2, CDK9, TROVE2, SRRT, PSPC1, FAM98B, GK, TXNRD1, NADKD1, NDUFS2, PCK2, CISD1, CYC1, UQCRFS1, MATR3, SRRT, NOP56, RIP1L1, UPF1, ZC3H14, HNRNPA0, LRPPRC, FARSA, EIF3D, MRPS22, NOP2, DNAJA2, NSUN2, DNAJA3, DDX5, DHX9, SFPQ, PPP1CB, PPP2R1A, BUB3, ILF3, ADAR, ISG15, NUP155, ZFR, ZC3H11A, KPNA4, KPNA1, KPNA3, KPNA6, ZNF326, SKIV2L2, SON, SUGP2, WTAP, PTBP1, PTBP3, CPSF1, RBM4, HNRNPUL2, SF1, SF3B1, PNN, ZCCHC8, SF3B3, CDC5L, PRPF8, SNRNP200, SAFB, PRMT5, WDR77, SUPT16H, SIRT1, SAP18, IKZF1, HCFC1, HDAC3, ZNF281, ZNF318, GIGYF2, RBM14, SAFB2, SPIN1, GTF21, MCM3, AKAP8L, TRIM28, PSMA2, PSME3, PSMB3, p53, USP11, SLC25A6, PFAS, CAD, SLC25A3, PFKL, ACLY, PPHLN1, RBM12B, or FLNA, or biologically active fragments thereof. Such antibodies can be polyclonal or monoclonal and can be, for example, murine, chimeric, humanized or fully human.

Polyclonal antibodies can be prepared by immunizing a suitable subject (e.g. a mouse) with a polypeptide immunogen (e.g., Table 3). The polypeptide antibody titer in the immunized subject can be monitored over time by standard techniques, such as with an enzyme linked immunosorbent assay (ELISA) using immobilized polypeptide. If desired, the antibody directed against the antigen can be isolated from the mammal (e.g., from the blood) and further purified by well-known techniques, such as protein A chromatography to obtain the IgG fraction.

At an appropriate time after immunization, e.g., when the antibody titers are highest, antibody-producing cells can be obtained from the subject and used to prepare monoclonal antibodies using standard techniques, such as the hybridoma technique originally described by Kohler and Milstein (1975) Nature 256:495-497) (see also Brown et al. (1981) J. Immunol. 127:539-46; Brown et al. (1980) J. Biol. Chem. 255:4980-83; Yeh et al. (1976) Proc. Natl. Acad. Sci. 76:2927-31; and Yeh et al. (1982) Int. J. Cancer 29:269-75), the more recent human B cell hybridoma technique (Kozbor et al. (1983) Immunol. Today 4:72), the EBV-hybridoma technique (Cole et al. (1985) Monoclonal Antibodies and Cancer Therapy, Alan R. Liss, Inc., pp. 77-96) or trioma techniques. The technology for producing monoclonal antibody hybridomas is well known (see generally Kenneth, R. H. in Monoclonal Antibodies: A New Dimension In Biological Analyses, Plenum Publishing Corp., New York, N.Y. (1980); Lerner, E. A. (1981) Yale J. Biol. Med. 54:387-402; Gefter, M. L. et al. (1977) Somatic Cell Genet. 3:231-36). Briefly, an immortal cell line (typically a myeloma) is fused to lymphocytes (typically splenocytes) from a mammal immunized with an immunogen as described above, and the culture supernatants of the resulting hybridoma cells are screened to identify a hybridoma producing a monoclonal antibody that binds to the polypeptide antigen, preferably specifically.

As an alternative to preparing monoclonal antibody-secreting hybridomas, a monoclonal specific for NHD and/or a polypeptide having an amino acid sequence selected from Table 3 can be identified and isolated by screening a recombinant combinatorial immunoglobulin library (e.g., an antibody phage display library or an antibody yeast display library) with the appropriate polypeptide (e.g., any of the proteins and sequences from Table 3) to thereby isolate immunoglobulin library members that bind the polypeptide.

Additionally, recombinant antibodies specific for NHD and/or a polypeptide having an amino acid sequence selected from Table 3, such as chimeric or humanized monoclonal antibodies, can be made using standard recombinant DNA techniques. Such chimeric and humanized monoclonal antibodies can be produced by recombinant DNA techniques known in the art, for example using methods described in U.S. Pat. Nos. 4,816,567; 5,565,332; Better et al. (1988) Science 240: 1041-1043; Liu et al. (1987) Proc. Natl. Acad. Sci. USA 84:3439-3443; Liu et al. (1987) J. Immunol. 139:3521-3526; Sun et al. (1987) Proc. Natl. Acad. Sci. 84:214-218; Nishimura et al. (1987) Cancer Res. 47:999-1005; Wood et al. (1985) Nature 314:446-449; and Shaw et al. (1988) J. Natl. Cancer Inst. 80: 1553-1559); Morrison, S. L. (1985) Science 229: 1202-1207; Oi et al. (1986) Biotechniques 4:214; Winter U.S. Pat. No. 5,225,539; Jones et al. (1986) Nature 321:552-525; Verhoeyan et al. (1988) Science 239: 1534; and Beidler et al. (1988) J. Immunol. 141:4053-4060.

Human monoclonal antibodies specific for NHD and/or a polypeptide having an amino acid sequence selected from Table 3 can be generated using transgenic or transchromosomal mice carrying parts of the human immune system rather than the mouse system. For example, “HuMAb mice” which contain a human immunoglobulin gene miniloci that encodes unrearranged human heavy (μ and γ) and κ light chain immunoglobulin sequences, together with targeted mutations that inactivate the endogenous μ and κ chain loci (Lonberg, N. et al. (1994) Nature 368(6474): 856 859). Accordingly, the mice exhibit reduced expression of mouse IgM or κ, and in response to immunization, the introduced human heavy and light chain transgenes undergo class switching and somatic mutation to generate high affinity human IgGK monoclonal antibodies (Lonberg, N. et al. (1994), supra; reviewed in Lonberg, N. (1994) Handbook of Experimental Pharmacology 113:49 101; Lonberg, N. and Huszar, D. (1995) Intern. Rev. Immunol. Vol. 13: 65 93, and Harding, F. and Lonberg, N. (1995) Ann. N. Y Acad. Sci 764:536 546). The preparation of HuMAb mice is described in Taylor, L. et al. (1992) Nucleic Acids Research 20:6287 6295; Chen, J. et al. (1993) International Immunology 5: 647 656; Tuaillon et al. (1993) Proc. Natl. Acad. Sci USA 90:3720 3724; Choi et al. (1993) Nature Genetics 4: 117 123; Chen, J. et al. (1993) EMBO J. 12: 821 830; Tuaillon et al. (1994) J Immunol. 152:2912 2920; Lonberg et al., (1994) Nature 368(6474): 856 859; Lonberg, N. (1994) Handbook of Experimental Pharmacology 113:49 101; Taylor, L. et al. (1994) International Immunology 6: 579 591; Lonberg, N. and Huszar, D. (1995) Intern. Rev. Immunol. Vol. 13: 65 93; Harding, F. and Lonberg, N. (1995) Ann. N.Y. Acad. Sci 764:536 546; Fishwild, D. et al. (1996) Nature Biotechnology 14: 845 851. See further, U.S. Pat. Nos. 5,545,806; 5,569,825; 5,625,126; 5,633,425; 5,789,650; 5,877,397; 5,661,016; 5,814,318; 5,874,299; 5,770,429; and 5,545,807.

In certain embodiments, the antibodies of the instant invention are able to bind to an epitope of NHD in a domain required for complex formation with PARP (e.g., a domain having an amino acid sequence selected from Table 3 with a dissociation constant of no greater than 10⁻⁶, 10⁻⁷, 10⁻⁸ or 10⁻⁹M. Standard assays to evaluate the binding ability of the antibodies are known in the art, including for example, ELISAs, Western blots and RIAs. The binding kinetics (e.g., binding affinity) of the antibodies also can be assessed by standard assays known in the art, such as by Biacore analysis. In some embodiments, the binding of the antibody to NHD (e.g., DBC1 or Table 3 proteins) substantially inhibits the ability of any of the proteins set forth in Table 4 to form a complex with NHD (e.g., DBC1 or Table 3 proteins). As used herein, an antibody substantially inhibits the ability of any of the proteins set forth in Table 4 to form a complex with NHD (e.g., DBC1 or Table 3 proteins) when an excess of antibody reduces the quantity of complex formed to by at least about 20%, 40%, 60% or 80%, 85% or 90% (as measured in an in vitro competitive binding assay).

2. Inhibitors of NHD Complex Formation

Certain embodiments of the present invention relate to methods of recovering from, treating, or preventing cancer, aging, cell death, radiation damage, radiation exposure, among others, improving DNA repair, cell proliferation, cell survival, among others, and increasing the life span of a cell or protecting it against certain stresses, among others. These methods include administering agents that reduce NHDs ability to complex with any of the proteins set forth in Table 4. For example, in certain embodiments the agent inhibits complex formation between NHD (e.g., DBC1 or Table 3 proteins) and any of the proteins set forth in Table 4. In some embodiments, the agents induce a conformational change in NHD (e.g., DBC1 or Table 3 proteins) or any of the proteins set forth in Table 4 that abrogates their interaction and/or alters the ability of NHD (e.g., DBC1 or Table 3 proteins) to affect any of the proteins set forth in Table 4 activity, protein levels or cell localization.

In some embodiments, any agent that reduces inhibition of any of the proteins set forth in Table 4 by NHD (e.g., DBC1 or Table 3 proteins) can be used to practice the methods of the invention. In some embodiments, the agent inhibits complex formation between NHD and any of the proteins set forth in Table 4. Such agents can be those described herein or those identified through routine screening assays (e.g. the screening assays described herein).

In some embodiments, assays used to identify agents useful in the methods of the present invention include a reaction between a polypeptide comprising a sequence selected from Table 3 or a biologically active fragment thereof and one or more assay components. The other components may be either a test compound (e.g. the potential agent), or a combination of test compounds and any of the proteins set forth in Table 4 protein or fragment thereof. Agents identified via such assays, may be useful, for example, for recovering from, preventing, or treating cancer, aging, cell death, radiation damage, radiation exposure, among others, improving DNA repair, cell proliferation, cell survival, among others, and increasing the life span of a cell or protecting it against certain stresses, among others.

Agents useful in the methods of the present invention may be obtained from any available source, including systematic libraries of natural and/or synthetic compounds. Agents may also be obtained by any of the numerous approaches in combinatorial library methods known in the art, including: biological libraries; peptoid libraries (libraries of molecules having the functionalities of peptides, but with a novel, non-peptide backbone which are resistant to enzymatic degradation but which nevertheless remain bioactive; see, e.g., Zuckermann et al., 1994, J. Med. Chem. 37:2678-85); spatially addressable parallel solid phase or solution phase libraries; synthetic library methods requiring deconvolution; the ‘one-bead one-compound’ library method; and synthetic library methods using affinity chromatography selection. The biological library and peptoid library approaches are limited to peptide libraries, while the other four approaches are applicable to peptide, non-peptide oligomer or small molecule libraries of compounds (Lam, 1997, Anticancer Drug Des. 12: 145).

Examples of methods for the synthesis of molecular libraries can be found in the art, for example in: DeWitt et al. (1993) Proc. Natl. Acad. Sci. U.S.A. 90:6909; Erb et al. (1994) Proc. Natl. Acad. Sci. USA 91: 11422; Zuckermann et al. (1994). J. Med. Chem. 37:2678; Cho et al. (1993) Science 261: 1303; Carrell et al. (1994) Angew. Chem. Int. Ed. Engl. 33:2059; Carell et al. (1994) Angew. Chem. Int. Ed. Engl. 33:2061; and in Gallop et al. (1994) J Med. Chem. 37: 1233. Libraries of agents may be presented in solution (e.g., Houghten, 1992, Biotechniques 13:412-421), or on beads (Lam, 1991, Nature 354:82-84), chips (Fodor, 1993, Nature 364:555-556), bacteria and/or spores, (Ladner, U.S. Pat. No. 5,223,409), plasmids (Cull et al, 1992, Proc Natl Acad Sci USA 89: 1865-1869) or on phage (Scott and Smith, 1990, Science 249:386-390; Devlin, 1990, Science 249:404-406; Cwirla et al, 1990, Proc. Natl. Acad. Sci. 87:6378-6382; Felici, 1991, J. Mol. Biol. 222:301-310; Ladner, supra.).

Agents useful in the methods of the present invention may be identified, for example, using assays for screening candidate or test compounds which inhibit complex formation between NHD (e.g., DBC1 or Table 3 proteins) and any of the proteins set forth in Table 4.

The basic principle of the assay systems used to identify compounds that inhibit complex formation between NHD (e.g., DBC1 or Table 3 proteins), and any of the proteins set forth in Table 4, involves preparing a reaction mixture containing a NHD (e.g., DBC1 or Table 3 proteins) protein or fragment thereof, and any of the proteins set forth in Table 4, or fragment thereof under conditions and for a time sufficient to allow the NHD (e.g., DBC1 or Table 3 proteins) protein or fragment thereof to form a complex with any of the proteins set forth in Table 4 or fragment thereof. In order to test an agent for modulatory activity, the reaction mixture is prepared in the presence and absence of the test compound. The test compound can be initially included in the reaction mixture, or can be added at a time subsequent to the addition of the NHD (e.g., DBC1 or Table 3 proteins) protein or fragment thereof, and any of the proteins set forth in Table 4 or fragment thereof. Control reaction mixtures are incubated without the test compound or with a placebo. The formation of any complexes between the NHD (e.g., DBC1 or Table 3 proteins) protein or fragment thereof, and any of the proteins set forth in Table 4 or fragment thereof, is then detected. The formation of a complex in the control reaction, but less or no such formation in the reaction mixture containing the test compound, indicates that the compound interferes with the interaction of the NHD (e.g., DBC1 or Table 3 proteins) protein or fragment thereof, and any of the proteins set forth in Table 4 or fragment thereof.

The assay for compounds that modulate the interaction of the NHD (e.g., DBC1 or Table 3 proteins) protein or fragment thereof, and any of the proteins set forth in Table 4 or fragment thereof, may be conducted in a heterogeneous or homogeneous format. Heterogeneous assays involve anchoring either the NHD (e.g., DBC1 or Table 3 proteins) protein or fragment thereof, or any of the proteins set forth in Table 4 or fragment, thereof onto a solid phase and detecting complexes anchored to the solid phase at the end of the reaction. In homogeneous assays, the entire reaction is carried out in a liquid phase. In either approach, the order of addition of reactants can be varied to obtain different information about the compounds being tested. For example, test compounds that interfere with the interaction between the NHD (e.g., DBC1 or Table 3 proteins) protein or fragment thereof, and any of the proteins set forth in Table 4 or fragment thereof (e.g., by competition), can be identified by conducting the reaction in the presence of the test substance, i.e., by adding the test substance to the reaction mixture prior to or simultaneously with the NHD (e.g., DBC1 or Table 3 proteins) protein or fragment thereof, and any of the proteins set forth in Table 4 or fragment thereof. Alternatively, test compounds that disrupt preformed complexes, e.g., compounds with higher binding constants that displace one of the components from the complex, can be tested by adding the test compound to the reaction mixture after complexes have been formed. The various formats are briefly described below.

In a heterogeneous assay system, either the NHD (e.g., DBC1 or Table 3 proteins) protein or fragment thereof, or any of the proteins set forth in Table 4 protein or fragment thereof, is anchored onto a solid surface or matrix, while the other corresponding non-anchored component may be labeled, either directly or indirectly. In practice, microtitre plates are often utilized for this approach. The anchored species can be immobilized by a number of methods, either non-covalent or covalent, that are typically well known to one who practices the art. Non-covalent attachment can often be accomplished simply by coating the solid surface with a solution of the NHD (e.g., DBC1 or Table 3 proteins) protein or fragment thereof, or any of the proteins set forth in Table 4 or fragment thereof, and drying. Alternatively, an immobilized antibody specific for the assay component to be anchored can be used for this purpose.

In related assays, a fusion protein can be provided which adds a domain that allows one or both of the assay components to be anchored to a matrix. For example, glutathione —S-transferase/marker fusion proteins or glutathione-S-transferase/binding partner can be adsorbed onto glutathione sepharose beads (Sigma Chemical, St. Louis, Mo.) or glutathione derivatized microtiter plates, which are then combined with the test compound or the test compound and either the non-adsorbed the NHD (e.g., DBC1 or Table 3 proteins) protein or fragment thereof, or any of the proteins set forth in Table 4 or fragment thereof, and the mixture incubated under conditions conducive to complex formation (e.g., physiological conditions). Following incubation, the beads or microtiter plate wells are washed to remove any unbound assay components, the immobilized complex assessed either directly or indirectly, for example, as described above.

A homogeneous assay may also be used to identify inhibitors of complex formation. This is typically a reaction, analogous to those mentioned above, which is conducted in a liquid phase in the presence or absence of the test compound. The formed complexes are then separated from unreacted components, and the amount of complex formed is determined. As mentioned for heterogeneous assay systems, the order of addition of reactants to the liquid phase can yield information about which test compounds modulate (inhibit or enhance) complex formation and which disrupt preformed complexes.

In such a homogeneous assay, the reaction products may be separated from unreacted assay components by any of a number of standard techniques, including but not limited to: differential centrifugation, chromatography, electrophoresis and immunoprecipitation. In differential centrifugation, complexes of molecules may be separated from uncomplexed molecules through a series of centrifugal steps, due to the different sedimentation equilibria of complexes based on their different sizes and densities (see, for example, Rivas, G., and Minton, A. P., Trends Biochem Sci 1993 August; 18(8):284-7). Standard chromatographic techniques may also be utilized to separate complexed molecules from uncomplexed ones. For example, gel filtration chromatography separates molecules based on size, and through the utilization of an appropriate gel filtration resin in a column format, for example, the relatively larger complex may be separated from the relatively smaller uncomplexed components. Similarly, the relatively different charge properties of the complex as compared to the uncomplexed molecules may be exploited to differentially separate the complex from the remaining individual reactants, for example through the use of ion-exchange chromatography resins. Such resins and chromatographic techniques are well known to one skilled in the art (see, e.g., Heegaard, 1998, J Mol. Recognit. 11: 141-148; Hage and Tweed, 1997, 1 Chromatogr. B. Biomed. Sci. Appl., 699:499-525). Gel electrophoresis may also be employed to separate complexed molecules from unbound species (see, e.g., Ausubel et al. (eds.), In: Current Protocols in Molecular Biology, J. Wiley & Sons, New York. 1999). In this technique, protein or nucleic acid complexes are separated based on size or charge, for example. In order to maintain the binding interaction during the electrophoretic process, nondenaturing gels in the absence of reducing agent are typically preferred, but conditions appropriate to the particular interactants will be well known to one skilled in the art. Immunoprecipitation is another common technique utilized for the isolation of a protein-protein complex from solution (see, e.g., Ausubel et al. (eds.), In: Current Protocols in Molecular Biology, J. Wiley & Sons, New York. 1999). In this technique, all proteins binding to an antibody specific to one of the binding molecules are precipitated from solution by conjugating the antibody to a polymer bead that may be readily collected by centrifugation. The bound assay components are released from the beads (through a specific proteolysis event or other technique well known in the art which will not disturb the protein-protein interaction in the complex), and a second immunoprecipitation step is performed, this time utilizing antibodies specific for the correspondingly different interacting assay component. In this manner, only formed complexes should remain attached to the beads. Variations in complex formation in both the presence and the absence of a test compound can be compared, thus offering information about the ability of the compound to modulate interactions between the NHD (e.g., DBC1 or Table 3 proteins) protein or fragment thereof, and any of the proteins set forth in Table 4 or fragment thereof.

Agents useful in the methods described herein may also be identified, for example, using methods wherein a cell (e.g., a cell that expresses NHD (e.g., DBC1 or Table 3 proteins) and any of the proteins set forth in Table 4), such as a mammalian cell) is contacted with a test compound, and the expression level of any of the proteins set forth in Table 4 target gene or a reporter gene under the transcriptional control of the promoter of a c-Myc target gene is determined. In some embodiments, any of the proteins set forth in Table 4 reporter gene encodes a readily detectable protein (e.g., a fluorescent protein or a protein catalyzes a reaction that produces a change in color, luminescence and/or opacity). In some embodiments, the level of expression of the reporter gene in the presence of the test compound is compared to the level of expression of mRNA or protein in the absence of the candidate compound. If the expression of the mRNA or protein increases in the presence of the test compound, the test compound an agent useful in the methods described herein.

3. NAD+, Analogs and Derivatives Thereof

The advantages of the present invention include, without limitation, compositions of nicotinamide mononucleotide, encompassing analogs and derivatives thereof, (e.g., NAD+) and their use in the methods provided herein (e.g., methods of recovering from, treating, and preventing cancer, aging, cell death, radiation damage, radiation exposure, among others, may improve DNA repair, cell proliferation, cell survival, among others, and may increase the life span of a cell or protect it against certain stresses, among others). In some embodiments, the invention relates to pharmaceutical compositions and nutritional supplements containing nicotinamide mononucleotide derivatives. In further embodiments, the invention relates to methods of using nicotinamide mononucleotide derivatives that promote the increase of intracellular levels of nicotinamide adenine dinucleotide (NAD+) in cells and tissues for recovering from, treating, or preventing diseases (e.g., cancer, aging, radiation damage, radiation exposure) and improving DNA repair, cell and tissue survival.

One embodiment of the nicotinamide mononucleotide, encompassing analogs and derivatives thereof, is a compound, its stereoisomer, salt, hydrate, solvate, or crystalline or polymorphic form thereof, represented by formula II:

-   -   wherein     -   (a) R¹ is hydrogen, n-alkyl; branched alkyl; cycloalkyl; or         aryl, which includes, but is not limited to, phenyl or naphthyl,         where phenyl or naphthyl are optionally substituted with at         least one of C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₁₋₆         alkoxy, F, Cl, Br, I, nitro, cyano, C₁₋₆ haloalkyl, C₁₋₆         acylamino, —NHSO₂C₁₋₆ alkyl, —SO₂N(R^(1′))₂, COR^(1″), and         —SO₂C₁₋₆ alkyl; (R^(1′) is independently hydrogen or alkyl,         which includes, but is not limited to, C₁₋₂₀ alkyl, C₁₋₁₀ alkyl,         or C₁₋₆ alkyl, R^(1″) is —OR′ or —N(R^(1′))₂);     -   (b) R² is hydrogen, C₁₋₁₀ alkyl, R^(3a) or R^(3b) and R²         together are (CH₂)_(n) so as to form a cyclic ring that includes         the adjoining N and C atoms, C(O)CR^(3a)R^(3b)NHR¹, where n is 2         to 4 and R′, R^(3a), and R^(3b);     -   (c) R^(3′) and R^(3b) are (i) independently selected from         hydrogen, C₁₋₁₀ alkyl, cycloalkyl, —(CH₂)_(c)(NR^(3′))₂, C₁₋₆         hydroxyalkyl, —CH₂SH, —(CH₂)₂S(O)_(d)Me, —(CH₂)₃NHC(═NH)NH₂,         (1H-indol-3-yl)methyl, (1H-imidazol-4-yl)methyl,         —(CH₂)_(e)COR^(3″), aryl and aryl C₁₋₃ alkyl, said aryl groups         optionally substituted with a group selected from hydroxyl,         C₁₋₁₀ alkyl, C₁₋₆ alkoxy, halogen, nitro and cyano; (ii) R^(1a)         and R^(3b) both are C₁₋₆ alkyl; (iii) R^(1a) and R^(3b) together         are (CH₂)_(f) so as to form a spiro ring; (iv) R^(1a) is         hydrogen and R^(3b) and R² together are (CH₂)_(n) so as to form         a cyclic ring that includes the adjoining N and C atoms (v)         R^(3b) is hydrogen and R^(1a) and R² together are (CH₂)_(n) so         as to form a cyclic ring that includes the adjoining N and C         atoms, where c is 1 to 6, d is 0 to 2, e is 0 to 3, f is 2 to 5,         n is 2 to 4, and where R^(3′) is independently hydrogen or C₁₋₆         alkyl and R^(3″) is —OR′ or —N(R^(3′))₂); (vi) R^(1a) is H and         R^(3b) is H, CH₃, CH₂CH₃, CH(CH₃)₂, CH₂CH(CH₃)₂, CH(CH₃)CH₂CH₃,         CH₂Ph, CH₂-indol-3-yl, —CH₂CH₂SCH₃, CH₂CO₂H, CH₂C(O)NH₂,         CH₂CH₂COOH, CH₂CH₂C(O)NH₂, CH₂CH₂CH₂CH₂NH₂,         —CH₂CH₂CH₂NHC(NH)NH₂, CH₂-imidazol-4-yl, CH₂OH, CH(OH)CH₃,         CH₂((4′-OH)-Ph), CH₂SH, or lower cycloalkyl; or (viii) R^(1a) is         CH₃, —CH₂CH₃, CH(CH₃)₂, CH₂CH(CH₃)₂, CH(CH₃)CH₂CH₃, CH₂Ph,         CH₂-indol-3-yl, —CH₂CH₂SCH₃, CH₂CO₂H, CH₂C(O)NH₂, CH₂CH₂COOH,         CH₂CH₂C(O)NH₂, CH₂CH₂CH₂CH₂NH₂, —CH₂CH₂CH₂NHC(NH)NH₂,         CH₂-imidazol-4-yl, CH₂OH, CH(OH)CH₃, CH₂((4′-OH)-Ph), CH₂SH, or         lower cycloalkyl and R^(3b) is H, where R^(3′) is independently         hydrogen or alkyl, which includes, but is not limited to, C₁₋₂₀         alkyl, C₁₋₁₀ alkyl, or C₁₋₆ alkyl, R^(3″) is —OR′ or         —N(R^(3′))₂); and     -   (d) R⁴ is hydrogen, C₁₋₁₀ alkyl, C₁₋₁₀ alkyl optionally         substituted with a lower alkyl, alkoxy, di(lower alkyl)-amino,         or halogen, C₁₋₁₀ haloalkyl, C₃₋₁₀ cycloalkyl, cycloalkyl alkyl,         cycloheteroalkyl, aminoacyl, aryl, such as phenyl, heteroaryl,         such as, pyridinyl, substituted aryl, or substituted heteroaryl.

Another embodiment of the nicotinamide mononucleotide, encompassing analogs and derivatives thereof, is a compound, its stereoisomer, salt, hydrate, solvate, or crystalline or polymorphic form thereof, wherein the compound is selected from the group consisting of

Yet another embodiment of the invention is a nicotinamide mononucleotide, encompassing analogs and derivatives thereof, for the treatment and/or prophylaxis of any of the diseases disclosed herein said composition comprising a pharmaceutically acceptable medium selected from among an excipient, carrier, diluent, and equivalent medium and a compound, its stereoisomer, salt, hydrate, solvate, or crystalline or polymorphic form thereof, represented by formula II:

-   -   wherein     -   (a) R¹ is hydrogen, n-alkyl; branched alkyl; cycloalkyl; or         aryl, which includes, but is not limited to, phenyl or naphthyl,         where phenyl or naphthyl are optionally substituted with at         least one of C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₁₋₆         alkoxy, F, Cl, Br, I, nitro, cyano, C₁₋₆ haloalkyl, C₁₋₆         acylamino, —NHSO₂C₁₋₆ alkyl, —SO₂N(R^(1′))₂, COR^(1″), and         —SO₂C₁₋₆ alkyl; (R′ is independently hydrogen or alkyl, which         includes, but is not limited to, C₁₋₂₀ alkyl, C₁₋₁₀ alkyl, or         C₁₋₆ alkyl, R^(1″) is —OR′ or —N(R^(1′))₂);     -   (b) R² is hydrogen, C₁₋₁₀ alkyl, R^(1a) or R^(3b) and R²         together are (CH₂)_(n) so as to form a cyclic ring that includes         the adjoining N and C atoms, C(O)CR^(3a)R^(3b)NHR¹, where n is 2         to 4 and R¹, R^(1a), and R^(3b);     -   (c) R^(1a) and R^(b) are (i) independently selected from         hydrogen, C₁₋₁₀ alkyl, cycloalkyl, —(CH₂)_(c)(NR^(3′))₂, C₁₋₆         hydroxyalkyl, —CH₂SH, —(CH₂)₂S(O)_(d)Me, —(CH₂)₃NHC(═NH)NH₂,         (1H-indol-3-yl)methyl, (1H-imidazol-4-yl)methyl,         —(CH₂)_(e)COR^(3″), aryl and aryl C₁₋₃ alkyl, said aryl groups         optionally substituted with a group selected from hydroxyl,         C₁₋₁₀ alkyl, C₁₋₆ alkoxy, halogen, nitro and cyano; (ii) R^(3′)         and R^(b) both are C₁₋₆ alkyl; (iii) R^(3a) and R^(3b) together         are (CH₂)_(r) so as to form a spiro ring; (iv) R^(3a) is         hydrogen and R^(3b) and R² together are (CH₂)_(n) so as to form         a cyclic ring that includes the adjoining N and C atoms (v)         R^(b) is hydrogen and R^(3a) and R² together are (CH₂)_(n) so as         to form a cyclic ring that includes the adjoining N and C atoms,         where c is 1 to 6, d is 0 to 2, e is 0 to 3, f is 2 to 5, n is 2         to 4, and where R^(3′) is independently hydrogen or C₁₋₆ alkyl         and R^(3″) is —OR′ or —N(R^(3′))₂); (vi) R^(3a) is H and R^(b)         is H, CH₃, CH₂CH₃, CH(CH₃)₂, CH₂CH(CH₃)₂, CH(CH₃)CH₂CH₃, CH₂Ph,         CH₂-indol-3-yl, —CH₂CH₂SCH₃, CH₂CO₂H, CH₂C(O)NH₂, CH₂CH₂COOH,         CH₂CH₂C(O)NH₂, CH₂CH₂CH₂CH₂NH₂, —CH₂CH₂CH₂NHC(NH)NH₂,         CH₂-imidazol-4-yl, CH₂OH, CH(OH)CH₃, CH₂((4′-OH)-Ph), CH₂SH, or         lower cycloalkyl; or (viii) R^(3a) is CH₃, —CH₂CH₃, CH(CH₃)₂,         CH₂CH(CH₃)₂, CH(CH₃)CH₂CH₃, CH₂Ph, CH₂-indol-3-yl, —CH₂CH₂SCH₃,         CH₂CO₂H, CH₂C(O)NH₂, CH₂CH₂COOH, CH₂CH₂C(O)NH₂, CH₂CH₂CH₂CH₂NH₂,         —CH₂CH₂CH₂NHC(NH)NH₂, CH₂-imidazol-4-yl, CH₂OH, CH(OH)CH₃,         CH₂((4′-OH)-Ph), CH₂SH, or lower cycloalkyl and R^(b) is H,         where R^(3′) is independently hydrogen or alkyl, which includes,         but is not limited to, C₁₋₂₀ alkyl, C₁₋₁₀ alkyl, or C₁₋₆ alkyl,         R^(3″) is —OR′ or —N(R^(3′))₂); and     -   (d) R⁴ is hydrogen, C₁₋₁₀ alkyl, C₁₋₁₀ alkyl optionally         substituted with a lower alkyl, alkoxy, di(lower alkyl)-amino,         or halogen, C₁₋₁₀ haloalkyl, C₃₋₁₀ cycloalkyl, cycloalkyl alkyl,         cycloheteroalkyl, aminoacyl, aryl, such as phenyl, heteroaryl,         such as, pyridinyl, substituted aryl, or substituted heteroaryl.

Another embodiment of the invention is method of treatment in a subject in need thereof, which comprises: administering a therapeutically effective amount of the compound represented by formula I to the subject; wherein the compound or its stereoisomer, salt, hydrate, solvate, or crystalline or polymorphic form thereof represented by formula II:

-   -   wherein     -   (a) R¹ is hydrogen, n-alkyl; branched alkyl; cycloalkyl; or         aryl, which includes, but is not limited to, phenyl or naphthyl,         where phenyl or naphthyl are optionally substituted with at         least one of C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₁₋₆         alkoxy, F, Cl, Br, I, nitro, cyano, C₁₋₆ haloalkyl, —N(R^(1′))₂,         C₁₋₆ acylamino, —NHSO₂C₁₋₆ alkyl, —SO₂N(R^(1′))₂, COR^(1″), and         —SO₂C₁₋₆ alkyl; (R^(1′) is independently hydrogen or alkyl,         which includes, but is not limited to, C₁₋₂₀ alkyl, C₁₋₁₀ alkyl,         or C₁₋₆ alkyl, R^(1″) is —OR′ or —N(R^(1′))₂);     -   (b) R² is hydrogen, C₁₋₁₀ alkyl, R^(1a) or R^(3b) and R²         together are (CH₂)_(n) so as to form a cyclic ring that includes         the adjoining N and C atoms, C(O)CR^(3a)R^(3b)NHR¹, where n is 2         to 4 and R′, R^(1a), and R^(3b);     -   (c) R^(1a) and R^(3b) are (i) independently selected from         hydrogen, C₁₋₁₀ alkyl, cycloalkyl, —(CH₂)_(e)(NR^(3′))₂, C₁₋₆         hydroxyalkyl, —CH₂SH, —(CH₂)₂S(O)_(d)Me, —(CH₂)₃NHC(═NH)NH₂,         (1H-indol-3-yl)methyl, (1H-imidazol-4-yl)methyl,         —(CH₂)_(e)COR³″, aryl and aryl C₁₋₃ alkyl, said aryl groups         optionally substituted with a group selected from hydroxyl,         C₁₋₁₀ alkyl, C₁₋₆ alkoxy, halogen, nitro and cyano; (ii) R^(1a)         and R^(3b) both are C₁₋₆ alkyl; (iii) R^(1a) and R^(3b) together         are (CH₂)f so as to form a spiro ring; (iv) R^(1a) is hydrogen         and R^(3b) and R² together are (CH₂)_(n) so as to form a cyclic         ring that includes the adjoining N and C atoms (v) R^(3b) is         hydrogen and R^(1a) and R² together are (CH₂)_(n) so as to form         a cyclic ring that includes the adjoining N and C atoms, where c         is 1 to 6, d is 0 to 2, e is 0 to 3, f is 2 to 5, n is 2 to 4,         and where R^(3′) is independently hydrogen or C₁₋₆ alkyl and         R^(3″) is —OR′ or —N(R^(3′))₂); (vi) R^(1a) is H and R^(3b) is         H, CH₃, CH₂CH₃, CH(CH₃)₂, CH₂CH(CH₃)₂, CH(CH₃)CH₂CH₃, CH₂Ph,         CH₂-indol-3-yl, —CH₂CH₂SCH₃, CH₂CO₂H, CH₂C(O)NH₂, CH₂CH₂COOH,         CH₂CH₂C(O)NH₂, CH₂CH₂CH₂CH₂NH₂, —CH₂CH₂CH₂NHC(NH)NH₂,         CH₂-imidazol-4-yl, CH₂OH, CH(OH)CH₃, CH₂((4′-OH)-Ph), CH₂SH, or         lower cycloalkyl; or (viii) R^(1a) is CH₃, —CH₂CH₃, CH(CH₃)₂,         CH₂CH(CH₃)₂, CH(CH₃)CH₂CH₃, CH₂Ph, CH₂-indol-3-yl, —CH₂CH₂SCH₃,         CH₂CO₂H, CH₂C(O)NH₂, CH₂CH₂COOH, CH₂CH₂C(O)NH₂, CH₂CH₂CH₂CH₂NH₂,         —CH₂CH₂CH₂NHC(NH)NH₂, CH₂-imidazol-4-yl, CH₂OH, CH(OH)CH₃,         CH₂((4′-OH)-Ph), CH₂SH, or lower cycloalkyl and R^(3b) is H,         where R^(3′) is independently hydrogen or alkyl, which includes,         but is not limited to, C₁₋₂₀ alkyl, C₁₋₁₀ alkyl, or C₁₋₆ alkyl,         R^(3″) is —OR′ or —N(R^(3′))₂); and     -   (d) R⁴ is hydrogen, C₁₋₁₀ alkyl, C₁₋₁₀ alkyl optionally         substituted with a lower alkyl, alkoxy, di(lower alkyl)-amino,         or halogen, C₁₋₁₀ haloalkyl, C₃₋₁₀ cycloalkyl, cycloalkyl alkyl,         cycloheteroalkyl, aminoacyl, aryl, such as phenyl, heteroaryl,         such as, pyridinyl, substituted aryl, or substituted heteroaryl.

In yet another embodiment is a method of treatment, wherein the compound, its stereoisomer, salt, hydrate, solvate, or crystalline or polymorphic form thereof, wherein the compound is selected from the group consisting of

An embodiment of the current invention is a compound, its stereoisomer, salt, hydrate, solvate, or crystalline or polymorphic form thereof, represented by formula III:

In which each W¹ and W² is independently

-   -   In an aspect of this embodiment, each R^(c) or R^(d) is         independently H, (C₁-C₈)alkyl, (C₂-C₈)alkenyl, (C₂-C₈)alkynyl,         (C₃-C₈)carbocyclyl, (C₄-C₈)carbocyclylalkyl, aryl(C₁-C₈)alkyl,         heterocyclyl(C₁-C₈)alkyl, (C₆-C₂₀)aryl, (C₂-C₂₀)heterocyclyl or         heteroaryl. In another aspect of this embodiment, each R^(c) is         H and each R^(d) is independently (C₁-C₈)alkyl, (C₂-C₈)alkenyl,         (C₂-C₈)alkynyl, (C₃-C₈)carbocyclyl, (C₄-C₈)carbocyclylalkyl,         aryl(C₁-C₈)alkyl, heterocyclyl(C₁-C₈)alkyl, (C₆-C₂₀)aryl,         (C₂-C₂₀)heterocyclyl or heteroaryl. In another aspect of this         embodiment, each R^(c) is H and each R^(d) is independently         (C₁-C₈)alkyl, (C₂-C₈)alkenyl, (C₂-C₈)alkynyl,         (C₃-C₈)carbocyclyl, (C₄-C₈)carbocyclylalkyl, aryl(C₁-C₈)alkyl,         heterocyclyl(C₁-C₈)alkyl, (C₆-C₂₀)aryl, (C₂-C₂₀)heterocyclyl or         heteroaryl wherein the chirality of the carbon to which said         R^(c) and R^(d) is attached is S. In another aspect of this         embodiment, each R^(c) is H and each R^(d) is independently         (C₁-C₈)alkyl, (C₂-C₈)alkenyl, (C₂-C₈)alkynyl,         (C₃-C₈)carbocyclyl, (C₄-C₈)carbocyclylalkyl, aryl(C₁-C₈)alkyl,         heterocyclyl(C₁-C₈)alkyl, (C₆-C₂₀)aryl, (C₂-C₂₀)heterocyclyl or         heteroaryl wherein the chirality of the carbon to which said         R^(c) and R^(d) is attached is R. In another aspect of this         embodiment, each R^(c) is H and each R^(d) is independently         (C₁-C₈)alkyl. In another aspect of this embodiment, each R^(c)         is H and each R^(d) is independently (C₁-C₈)alkyl wherein the         chirality of the carbon to which said R^(c) and R^(d) is         attached is S. In another aspect of this embodiment, each R^(c)         is H and each R^(d) is independently (C₁-C₈)alkyl wherein the         chirality of the carbon to which said R^(c) and R^(d) is         attached is R. In another aspect of this embodiment, each

comprises a nitrogen-linked naturally occurring α-amino acid ester.

In another embodiment of Formula III, each W¹ and W² is independently

and each R⁶ is independently (C₁-C₈)alkyl, (C₂-C₈)alkenyl, (C₂-C₈)alkynyl, (C₃-C₈)carbocyclyl or (C₄-C₈)carbocyclylalkyl. In another aspect of this embodiment, each R⁶ is independently (C₁-C₈)alkyl. In another aspect of this embodiment, each R^(c) or R^(d) is independently H, (C₁-C₈)alkyl, (C₂-C₈)alkenyl, (C₂-C₈)alkynyl, (C₃-C₈)carbocyclyl, (C₄-C₈)carbocyclylalkyl, aryl(C₁-C₈)alkyl, heterocyclyl(C₁-C₈)alkyl, (C₆-C₂₀)aryl, (C₂-C₂₀)heterocyclyl or heteroaryl. In another aspect of this embodiment, each R^(c) is H and each R^(d) is independently (C₁-C₈)alkyl, (C₂-C₈)alkenyl, (C₂-C₈)alkynyl, (C₃-C₈)carbocyclyl, (C₄-C₈)carbocyclylalkyl, aryl(C₁-C₈)alkyl, heterocyclyl(C₁-C₈)alkyl, (C₆-C₂₀)aryl, (C₂-C₂₀)heterocyclyl or heteroaryl. In another aspect of this embodiment, each R^(c) is H and each R^(d) is independently (C₁-C₈)alkyl, (C₂-C₈)alkenyl, (C₂-C₈)alkynyl, (C₃-C₈)carbocyclyl, (C₄-C₈)carbocyclylalkyl, aryl(C₁-C₈)alkyl, heterocyclyl(C₁-C₈)alkyl, (C₆-C₂₀)aryl, (C₂-C₂₀)heterocyclyl or heteroaryl wherein the chirality of the carbon to which said R^(c) and R^(d) is attached is S. In another aspect of this embodiment, each R^(c) is H and each R^(d) is independently (C₁-C₈)alkyl, (C₂-C₈)alkenyl, (C₂-C₈)alkynyl, (C₃-C₈)carbocyclyl, (C₄-C₈)carbocyclylalkyl, aryl(C₁-C₈)alkyl, heterocyclyl(C₁-C₈)alkyl, (C₆-C₂₀)aryl, (C₂-C₂₀)heterocyclyl or heteroaryl wherein the chirality of the carbon to which said R^(c) and R^(d) is attached is R. In another aspect of this embodiment, each R^(c) is H and each R^(d) is independently (C₁-C₈)alkyl. In another aspect of this embodiment, each R^(c) is H and each R^(d) is independently (C₁-C₈)alkyl wherein the chirality of the carbon to which said R^(c) and R^(d) is attached is S. In another aspect of this embodiment, each R^(c) is H and each R^(d) is independently (C₁-C₈)alkyl wherein the chirality of the carbon to which said R^(c) and R^(d) is attached is R. In another aspect of this embodiment, each

comprises a nitrogen-linked naturally occurring α-amino acid ester.

In one embodiment of Formula III, each W¹ and W² is independently

and each R⁶ is independently (C₁-C₈)alkyl. In another aspect of this embodiment, each R⁶ is independently secondary alkyl. In another aspect of this embodiment, each R⁶ is 2-propyl. In another aspect of this embodiment, each R^(c) is H and each R^(d) is methyl. In another aspect of this embodiment, each R^(c) is H and each R^(d) is methyl wherein the chirality of the carbon to which said R^(c) and R^(d) is attached is S. In another aspect of this embodiment, each R^(c) is H and each R^(d) is methyl wherein the chirality of the carbon to which said R^(c) and R^(d) is attached is R. In another aspect of this embodiment, R¹ is H. In another aspect of this embodiment, R¹ is (C₁-C₈)alkyl. In another aspect of this embodiment, R¹ is methyl. In another aspect of this embodiment, R¹ is (C₁-C₈)alkyl and R² is OH. In another aspect of this embodiment, R¹ is (C₁-C₈)alkyl, R² is OH and R³ is (C₁-C₈)alkyl. In another aspect of this embodiment, R¹ is methyl and R² is OH. In another aspect of this embodiment, R¹ is methyl, R² is OH and R³ is (C₁-C₈)alkyl. In another aspect of this embodiment, each

comprises a nitrogen-linked naturally occurring α-amino acid ester.

In one embodiment of Formula III, one of W¹ or W² is OR⁴ and the other of W¹ or W² is

In another aspect of this embodiment, R⁴ is (C₁-C₈)alkyl, (C₂-C₈)alkenyl, (C₂-C₈)alkynyl, (C₃-C₈)carbocyclyl, (C₄-C₈)carbocyclylalkyl, aryl(C₁-C₈)alkyl, heterocyclyl(C₁-C₈)alkyl, (C₆-C₂₀)aryl, (C₂-C₂₀)heterocyclyl or heteroaryl. In another aspect of this embodiment, R⁴ is (C₆-C₂₀)aryl, (C₂-C₂₀)heterocyclyl or heteroaryl. In another aspect of this embodiment, R⁴ is (C₆-C₂₀)aryl. In another aspect of this embodiment, R⁴ is phenyl wherein said phenyl is optionally substituted with one or more halo, hydroxy, CN, N₃, N(R^(a))₂, NH(R^(a)), NH₂, C(O)N(R^(a))₂, C(O)NH(R^(a)), C(O)NH₂, OC(O)N(R^(a))₂, OC(O)NH(R^(a)), OC(O)NH₂, C(O)OR^(a), OC(O)OR^(a), S(O)_(n)R^(a), S(O)₂N(R^(a))₂, S(O)₂NH(R^(a)), S(O)₂NH₂, OR^(a) or R^(a). In another aspect of this embodiment, each

comprises a nitrogen-linked naturally occurring α-amino acid ester.

In one embodiment of Formula III, one of W¹ or W² is OR⁴ and the other of W¹ or W² is

wherein R⁴ is unsubstituted phenyl. In another aspect of this embodiment, R¹ is H. In another aspect of this embodiment, R¹ is (C₁-C₈)alkyl. In another aspect of this embodiment, R¹ is methyl. In another aspect of this embodiment, R¹ is (C₁-C₈)alkyl and R² is OH. In another aspect of this embodiment, R¹ is (C₁-C₈)alkyl, R² is OH and R³ is (C₁-C₈)alkyl. In another aspect of this embodiment, R¹ is methyl and R² is OH. In another aspect of this embodiment, R¹ is methyl, R² is OH and R³ is (C₁-C₈)alkyl. In another aspect of this embodiment, each R^(c) or R^(d) is independently H, (C₁-C₈)alkyl, (C₂-C₈)alkenyl, (C₂-C₈)alkynyl, (C₃-C₈)carbocyclyl, (C₄-C₈)carbocyclylalkyl, aryl(C₁-C₈)alkyl, heterocyclyl(C₁-C₈)alkyl, (C₆-C₂₀)aryl, (C₂-C₂₀)heterocyclyl or heteroaryl. In another aspect of this embodiment, one of R^(c) or R^(d) is H and the other of R^(c) or R^(d) is (C₁-C₈)alkyl, (C₂-C₈)alkenyl, (C₂-C₈)alkynyl, (C₃-C₈)carbocyclyl, (C₄-C₈)carbocyclylalkyl, aryl(C₁-C₈)alkyl, heterocyclyl(C₁-C₈)alkyl, (C₆-C₂₀)aryl, (C₂-C₂₀)heterocyclyl or heteroaryl. In another aspect of this embodiment, one of R^(c) or R^(d) is H and the other of R^(c) or R^(d) is (C₁-C₈)alkyl, (C₂-C₈)alkenyl, (C₂-C₈)alkynyl, (C₃-C₈)carbocyclyl, (C₄-C₈)carbocyclylalkyl, aryl(C₁-C₈)alkyl, heterocyclyl(C₁-C₈)alkyl, (C₆-C₂₀)aryl, (C₂-C₂₀)heterocyclyl or heteroaryl wherein the chirality of the carbon to which said R^(c) and R^(d) is attached is S. In another aspect of this embodiment, one of R^(c) or R^(d) is H and the other of R^(c) or R^(d) is independently (C₁-C₈)alkyl, (C₂-C₈)alkenyl, (C₂-C₈)alkynyl, (C₃-C₈)carbocyclyl, (C₄-C₈)carbocyclylalkyl, aryl(C₁-C₈)alkyl, heterocyclyl(C₁-C₈)alkyl, (C₆-C₂₀)aryl, (C₂-C₂₀)heterocyclyl or heteroaryl wherein the chirality of the carbon to which said R^(c) and R^(d) is attached is R. In another aspect of this embodiment, one of R^(c) or R^(d) is H and the other of R^(c) or R^(d) is (C₁-C₈)alkyl. In another aspect of this embodiment, one of R^(c) or R^(d) is H and the other of R^(c) or R^(d) is (C₁-C₈)alkyl wherein the chirality of the carbon to which said R^(c) and R^(d) is attached is S. In another aspect of this embodiment, one of R^(c) or R^(d) is H and the other of R^(c) or R^(d) is (C₁-C₈)alkyl wherein the chirality of the carbon to which said R^(c) and R^(d) is attached is R. In another aspect of this embodiment, the chirality at phosphorus is S. In another aspect of this embodiment, the chirality at phosphorus is R. In another aspect of this embodiment, each

comprises a nitrogen-linked naturally occurring α-amino acid ester.

In one embodiment of Formula III, one of W¹ or W² is OR⁴ and the other of W or W² is

wherein one of R^(c) or R^(d) is H and the other of R^(c) or R^(d) is methyl. In another aspect of this embodiment, one of R^(c) or R^(d) is H and the other of R^(c) or R^(d) is methyl wherein the chirality of the carbon to which said R^(c) and R^(d) is attached is S. In another aspect of this embodiment, one of R^(c) or R^(d) is H and the other of R^(c) or R^(d) is methyl wherein the chirality of the carbon to which said R^(c) and R^(d) is attached is R. In another aspect of this embodiment, R⁴ is phenyl wherein said phenyl is optionally substituted with one or more halo, hydroxy, CN, N₃, N(R^(a))₂, NH(R^(a)), NH₂, C(O)N(R^(a))₂, C(O)NH(R^(a)), C(O)NH₂, OC(O)N(R^(a))₂, OC(O)NH(R^(a)), OC(O)NH₂, C(O)OR^(a), OC(O)OR^(a), S(O)_(n)R^(a), S(O)₂N(R^(a))₂, S(O)₂NH(R^(a)), S(O)₂NH₂, OR^(a) or R^(a). In another aspect of this embodiment, R¹ is H. In another aspect of this embodiment, R¹ is (C₁-C₈)alkyl. In another aspect of this embodiment, R¹ is methyl. In another aspect of this embodiment, R¹ is (C₁-C₈)alkyl and R² is OH. In another aspect of this embodiment, R¹ is (C₁-C₈)alkyl, R² is OH and R³ is (C₁-C₈)alkyl. In another aspect of this embodiment, R¹ is methyl and R² is OH. In another aspect of this embodiment, R¹ is methyl, R² is OH and R³ is (C₁-C₈)alkyl. In another aspect of this embodiment, the chirality at phosphorus is S. In another aspect of this embodiment, the chirality at phosphorus is R. In another aspect of this embodiment, each

comprises a nitrogen-linked naturally occurring α-amino acid ester.

In one embodiment of Formula III, one of W¹ or W² is OR⁴ and the other of W¹ or W² is

wherein R⁴ is unsubstituted phenyl, one of R^(c) or R^(d) is H and the other of R^(c) or R^(d) is methyl. In another aspect of this embodiment, the chirality at phosphorous is R. In another aspect of this embodiment, the chirality at phosphorous is S. In another aspect of this embodiment, the chirality of the carbon to which said R^(c) and R^(d) is attached is S. In another aspect of this embodiment, the chirality of the carbon to which said R^(c) and R^(d) is attached is S and the chirality at phosphorus is S. In another aspect of this embodiment, the chirality of the carbon to which said R^(c) and R^(d) is attached is S and the chirality at phosphorus is R. In another aspect of this embodiment, the chirality of the carbon to which said R^(c) and R^(d) is attached is R. In another aspect of this embodiment, the chirality of the carbon to which said R^(c) and R^(d) is attached is R and the chirality at phosphorus is S. In another aspect of this embodiment, the chirality of the carbon to which said R^(c) and R^(d) is attached is R and the chirality at phosphorus is R. In another aspect of this embodiment, R¹ is H. In another aspect of this embodiment, R¹ is (C₁-C₈)alkyl. In another aspect of this embodiment, R¹ is methyl. In another aspect of this embodiment, R¹ is (C₁-C₈)alkyl and R² is OH. In another aspect of this embodiment, R¹ is (C₁-C₈)alkyl, R² is OH and R³ is (C₁-C₈)alkyl. In another aspect of this embodiment, R¹ is methyl and R² is OH. In another aspect of this embodiment, R¹ is methyl, R² is OH and R³ is (C₁-C₈)alkyl. In another aspect of this embodiment, each

comprises a nitrogen-linked naturally occurring α-amino acid ester.

In one embodiment of Formula III, one of W¹ or W² is OR⁴ and the other of W¹ or W² is

wherein R⁴ is unsubstituted phenyl and R⁶ is (C₁-C₈)alkyl, (C₂-C₈)alkenyl, (C₂-C₈)alkynyl, (C₃-C₈)carbocyclyl, (C₄-C₈)carbocyclylalkyl. In another aspect of this embodiment, R⁶ is (C₁-C₈)alkyl. In another aspect of this embodiment, one of R^(c) or R^(d) is H and the other of R^(c) or R^(d) is (C₁-C₈)alkyl, (C₂-C₈)alkenyl, (C₂-C₈)alkynyl, (C₃-C₈)carbocyclyl, (C₄-C₈)carbocyclylalkyl, aryl(C₁-C₈)alkyl, heterocyclyl(C₁-C₈)alkyl, (C₆-C₂₀)aryl, (C₂-C₂₀)heterocyclyl or heteroaryl. In another aspect of this embodiment, one of R^(c) or R^(d) is H and the other of R^(c) or R^(d) is (C₁-C₈)alkyl, (C₂-C₈)alkenyl, (C₂-C₈)alkynyl, (C₃-C₈)carbocyclyl, (C₄-C₈)carbocyclylalkyl, aryl(C₁-C₈)alkyl, heterocyclyl(C₁-C₈)alkyl, (C₆-C₂₀)aryl, (C₂-C₂₀)heterocyclyl or heteroaryl wherein the chirality of the carbon to which said R^(c) and R^(d) is attached is S. In another aspect of this embodiment, one of R^(c) or R^(d) is H and the other of R^(c) or R^(d) is (C₁-C₈)alkyl, (C₂-C₈)alkenyl, (C₂-C₈)alkynyl, (C₃-C₈)carbocyclyl, (C₄-C₈)carbocyclylalkyl, aryl(C₁-C₈)alkyl, heterocyclyl(C₁-C₈)alkyl, (C₆-C₂₀)aryl, (C₂-C₂₀)heterocyclyl or heteroaryl wherein the chirality of the carbon to which said R^(c) and R^(d) is attached is R. In another aspect of this embodiment, one of R^(c) or R^(d) is H and the other of R^(c) or R^(d) is (C₁-C₈)alkyl. In another aspect of this embodiment, one of R^(c) or R^(d) is H and the other of R^(c) or R^(d) is (C₁-C₈)alkyl wherein the chirality of the carbon to which said R^(c) and R^(d) is attached is S. In another aspect of this embodiment, one of R^(c) or R^(d) is H and the other of R^(c) or R^(d) is (C₁-C₈)alkyl wherein the chirality of the carbon to which said R^(c) and R^(d) is attached is R. In another aspect of this embodiment, the chirality at phosphorus is S. In another aspect of this embodiment, the chirality at phosphorus is R. In another aspect of this embodiment, each

comprises a nitrogen-linked naturally occurring α-amino acid ester.

In one embodiment of Formula III, one of W¹ or W² is OR⁴ and the other of W¹ or W² is

wherein one of R^(c) or R^(d) is H and the other of R^(c) or R^(d) is methyl and R⁶ is (C₁-C₈)alkyl. In another aspect of this embodiment, R⁶ is secondary alkyl. In another aspect of this embodiment, R⁶ is 2-propyl. In another aspect of this embodiment, the chirality of the carbon to which said R^(c) and R^(d) is attached is S. In another aspect of this embodiment, chirality of the carbon to which said R^(c) and R^(d) is attached is R. In another aspect of this embodiment, R⁴ is phenyl wherein said phenyl is optionally substituted with one or more halo, hydroxy, CN, N₃, N(R^(a))₂, NH(R^(a)), NH₂, C(O)N(R^(a))₂, C(O)NH(R^(a)), C(O)NH₂, OC(O)N(R^(a))₂, OC(O)NH(R^(a)), OC(O)NH₂, C(O)OR^(a), OC(O)OR^(a), S(O),R^(a), S(O)₂N(R^(a))₂, S(O)₂NH(R^(a)), S(O)₂NH₂, OR^(a) or R^(a). In another aspect of this embodiment, R¹ is H. In another aspect of this embodiment, R¹ is (C₁-C₈)alkyl. In another aspect of this embodiment, R¹ is methyl. In another aspect of this embodiment, R¹ is (C₁-C₈)alkyl and R² is OH. In another aspect of this embodiment, R¹ is (C₁-C₈)alkyl, R² is OH and R³ is (C₁-C₈)alkyl. In another aspect of this embodiment, R¹ is methyl and R² is OH. In another aspect of this embodiment, R¹ is methyl, R² is OH and R³ is (C₁-C₈)alkyl. In another aspect of this embodiment, the chirality at phosphorus is S. In another aspect of this embodiment, the chirality at phosphorus is R. In another aspect of this embodiment, each

comprises a nitrogen-linked naturally occurring α-amino acid ester.

In one embodiment of Formula III, one of W¹ or W² is OR⁴ and the other of W¹ or W² is

wherein R⁴ is unsubstituted phenyl, one of R^(c) or R^(d) is H and the other of R^(c) or R^(d) is methyl and R⁶ is (C₁-C₈)alkyl. In another aspect of this embodiment, R⁶ is secondary alkyl. In another aspect of this embodiment, R⁶ is 2-propyl. In another aspect of this embodiment, the chirality of the carbon to which said R^(c) and R^(d) is attached is S. In another aspect of this embodiment, chirality of the carbon to which said R^(c) and R^(d) is attached is R. In another aspect of this embodiment, R¹ is H. In another aspect of this embodiment, R¹ is (C₁-C₈)alkyl. In another aspect of this embodiment, R¹ is methyl. In another aspect of this embodiment, R¹ is (C₁-C₈)alkyl and R² is OH. In another aspect of this embodiment, R¹ is (C₁-C₈)alkyl, R² is OH and R³ is (C₁-C₈)alkyl. In another aspect of this embodiment, R¹ is methyl and R² is OH. In another aspect of this embodiment, R¹ is methyl, R² is OH and R³ is (C₁-C₈)alkyl. In another aspect of this embodiment, the chirality at phosphorus is S. In another aspect of this embodiment, the chirality at phosphorus is R. In another aspect of this embodiment, R⁸ is halogen, NR¹¹R¹², OR¹¹, or SR¹¹. In another aspect of this embodiment, R⁸ is halogen. In another aspect of this embodiment, R⁸ is NH₂. In another aspect of this embodiment, R⁸ is OR¹¹. In another aspect of this embodiment, R⁸ is OH. In another aspect of this embodiment, R⁸ is SR¹¹. In another aspect of this embodiment, R⁸ is SH. In another aspect of this embodiment, R⁹ is H, halogen, NR¹¹R¹², OR¹¹, or SR¹¹. In another aspect of this embodiment, R⁹ is H. In another aspect of this embodiment, R⁹ is halogen. In another aspect of this embodiment, R⁹ is NR¹¹R¹². In another aspect of this embodiment, R⁹ is NH₂. In another aspect of this embodiment, R⁹ is OR¹¹. In another aspect of this embodiment, R⁹ is OH. In another aspect of this embodiment, R⁹ is SR¹¹. In another aspect of this embodiment, R⁹ is SH. In another aspect of this embodiment, each

comprises a nitrogen-linked naturally occurring α-amino acid ester.

In another embodiment of Formula III, R⁸ is halogen, NR¹¹R¹², OR¹¹, or SR¹¹. In another aspect of this embodiment, R⁸ is halogen. In another aspect of this embodiment, R⁸ is NH₂. In another aspect of this embodiment, R⁸ is OR¹¹. In another aspect of this embodiment, R⁸ is OH. In another aspect of this embodiment, R⁸ is SR¹¹. In another aspect of this embodiment, R⁸ is SH. In another aspect of this embodiment, R⁹ is H, halogen, NR¹¹R¹², OR¹¹, or SR¹¹. In another aspect of this embodiment, R⁹ is H. In another aspect of this embodiment, R⁹ is halogen. In another aspect of this embodiment, R⁹ is NR¹¹R¹². In another aspect of this embodiment, R⁹ is NH₂. In another aspect of this embodiment, R⁹ is OR¹¹. In another aspect of this embodiment, R⁹ is OH. In another aspect of this embodiment, R⁹ is SR¹¹. In another aspect of this embodiment, R⁹ is SH.

In another embodiment of Formula III, R⁸ is NH₂ and R⁹ is H. In another aspect of this embodiment, R¹ is H. In another aspect of this embodiment, R¹ is (C₁-C₈)alkyl. In another aspect of this embodiment, R¹ is (C₂-C₈)alkenyl. In another aspect of this embodiment, R¹ is (C₂-C₈)alkynyl. In another aspect of this embodiment, R² is OH. In another aspect of this embodiment, R² is OH and R³ is (C₁-C₈)alkyl. In another aspect of this embodiment, each R^(c) is H and each R^(d) is methyl. In another aspect of this embodiment, each R^(c) is H and each R^(d) is methyl wherein the chirality of the carbon to which each said R^(c) and R^(d) is attached is S. In another aspect of this embodiment, each R^(c) is H and each R^(d) is methyl wherein the chirality of the carbon to which each said R^(c) and R^(d) is attached is R. In another aspect of this embodiment, R⁴ is phenyl wherein said phenyl is optionally substituted with one or more halo, hydroxy, CN, N₃, N(R^(a))₂, NH(R^(a)), NH₂, C(O)N(R^(a))₂, C(O)NH(R^(a)), C(O)NH₂, OC(O)N(R^(a))₂, OC(O)NH(R^(a)), OC(O)NH₂, C(O)OR^(a), OC(O)OR^(a), S(O)_(n)R^(a), S(O)₂N(R^(a))₂, S(O)₂NH(R^(a)), S(O)₂NH₂, OR^(a) or R^(a).

In another embodiment of Formula III, R⁸ is NH₂, R⁹ is H and R¹ is (C₁-C₈)alkyl. In another aspect of this embodiment, R² is OH. In another aspect of this embodiment, R² is OH and R³ is (C₁-C₈)alkyl. In another aspect of this embodiment, each R⁶ is independently (C₁-C₈)alkyl. In another aspect of this embodiment, each R⁶ is independently secondary alkyl. In another aspect of this embodiment, each W¹ and W² is independently

In another aspect of this embodiment, one of W¹ or W² is OR⁴ and the other of W¹ or W² is

In another aspect of this embodiment, each

comprises a nitrogen-linked naturally occurring α-amino acid ester.

In another embodiment of Formula III, R⁸ is NH₂, R⁹ is H and one of W¹ or W² is OR⁴ and the other of W¹ or W² is

In another aspect of this embodiment, one of R^(c) or R^(d) is H and the other of R^(c) or R^(d) is methyl. In another aspect of this embodiment, one of R^(c) or R^(d) is H and the other of R^(c) or R^(d) is methyl wherein the chirality of the carbon to which said R^(c) and R^(d) is attached is S. In another aspect of this embodiment, one of R^(c) or R^(d) is H and the other of R^(c) or R^(d) is methyl wherein the chirality of the carbon to which said R^(c) and R^(d) is attached is R. In another aspect of this embodiment, R⁴ is phenyl wherein said phenyl is optionally substituted with one or more halo, hydroxy, CN, N₃, N(R^(a))₂, NH(R^(a)), NH₂, C(O)N(R^(a))₂, C(O)NH(R^(a)), C(O)NH₂, OC(O)N(R^(a))₂, OC(O)NH(R^(a)), OC(O)NH₂, C(O)OR^(a), OC(O)OR^(a), C(O)R^(a), OC(O)R^(a), S(O)_(n)R^(a), S(O)₂N(R^(a))₂, S(O)₂NH(R^(a)), S(O)₂NH₂, OR^(a) or R^(a). In another aspect of this embodiment, the chirality at phosphorus is S. In another aspect of this embodiment, the chirality at phosphorus is R. In another aspect of this embodiment, each

comprises a nitrogen-linked naturally occurring α-amino acid ester.

In another embodiment of Formula III, R⁸ is NH₂, R⁹ is H, R¹ is (C₁-C₈)alkyl and one of W¹ or W² is OR⁴ and the other of W¹ or W² is

In another aspect of this embodiment, R² is OH. In another aspect of this embodiment, R² is OH and R³ is (C₁-C₈)alkyl. In another aspect of this embodiment, R⁶ is (C₁-C₈)alkyl. In another aspect of this embodiment, R⁶ is secondary alkyl. In another aspect of this embodiment, one of R^(c) or R^(d) is H and the other of R^(c) or R^(d) is methyl. In another aspect of this embodiment, one of R^(c) or R^(d) is H and the other of R^(c) or R^(d) is methyl wherein the chirality of the carbon to which said R^(c) and R^(d) is attached is S. In another aspect of this embodiment, one of R^(c) or R^(d) is H and the other of R^(c) or R^(d) is methyl wherein the chirality of the carbon to which said R^(c) and R^(d) is attached is R. In another aspect of this embodiment, R⁴ is phenyl wherein said phenyl is optionally substituted with one or more halo, hydroxy, CN, N₃, N(R^(a))², NH(R^(a)), NH₂, C(O)N(R^(a))₂, C(O)NH(R^(a)), C(O)NH₂, OC(O)N(R^(a))₂, OC(O)NH(R^(a)), OC(O)NH₂, C(O)OR^(a), OC(O)OR^(a), C(O)R^(a), OC(O)R^(a), S(O)_(n)R^(a), S(O)₂N(R^(a))₂, S(O)₂NH(R^(a)), S(O)₂NH₂, OR^(a) or R^(a). In another aspect of this embodiment, the chirality at phosphorus is S. In another aspect of this embodiment, the chirality at phosphorus is R. In another aspect of this embodiment, each

comprises a nitrogen-linked naturally occurring α-amino acid ester.

In another embodiment of Formula III, R⁸ is NH₂ and R⁹ is NH₂.

In another embodiment of Formula III, R⁸ is OH and R⁹ is NH₂.

In another embodiment of Formula III, R⁸ is OH and R⁹ is OH.

In another embodiment of Formula III, R⁸ is OH and R⁹ is OH.

An embodiment of the current invention is a compound, its stereoisomer, salt, hydrate, solvate, or crystalline or polymorphic form thereof, represented by formula III:

wherein W¹ and W² are independently selected from the group consisting of the substituents in Table 1. Synthesis and general descriptions of representative substituents can be found, for instance, in U.S. Pat. No. 8,318,682, incorporated herein by reference. The variables used in Table 1 (e.g., W²³, R²¹, etc.) pertain only to Table 1, unless otherwise indicated.

The variables used in Table 1 have the following definitions:

-   -   each R²¹ is independently H or (C¹-C⁸)alkyl;     -   each R²² is independently H, R²¹, R²³ or R²⁴ wherein each R²⁴ is         independently substituted with 0 to 3 R²³;     -   each R²³ is independently R^(23a), R^(23b), R^(23c) or R^(23d),         provided that when R²³ is bound to a heteroatom, then R²³ is         R^(23c) or R^(23d);     -   each R^(23a) is independently F, Cl, Br, I, —CN, N₃ or —NO₂;     -   each R^(23b) is independently Y²¹;     -   each R^(23c) is independently —N(R^(2x))(R^(2x)), —SR^(2x),         —S(O)R^(2x); —S(O)₂R^(2x), —S(O)(OR^(2x)), —S(O)₂(OR^(2x)),         —OC(═Y²¹)R^(2x), —OC(═Y²¹)OR^(2x), —OC(═Y²¹)(N(R^(2x))(R^(2x)));         —SC(═Y²¹)R^(2x); —SC(═Y²¹)OR^(2x); —SC(═Y²¹)(N(R^(2x))(R^(2x)));         —N(R^(2x))C(═Y²¹)R^(2x), —N(R^(2x))C(═(Y²¹)OR^(2x); or         —N(R^(2x))C(═Y²¹)(N(R^(2x))(R^(2x))); each R^(23d) is         independently —C(═Y²¹)R^(2x); —C(Y²¹)OR^(2x) or         —C(Y²¹)(N(R^(2x)(R^(2x))); each R^(2x) is independently H,         (C₁-C₈)alkyl, (C₂-C₈)alkenyl, (C₂-C₈)alkynyl, aryl, heteroaryl;         or two R^(2x) taken together with a nitrogen to which they are         both attached form a 3 to 7 membered heterocyclic ring wherein         any one carbon atom of said heterocyclic ring can optionally be         replaced with —O—, —S— or —NR²¹—; and     -   wherein one or more of the non-terminal carbon atoms of each         said (C₁-C₈)alkyl may be optionally replaced with —O—, —S— or         —NR²¹—;     -   each R²⁴ is independently (C₁-C₈)alkyl, (C₂-C₈)alkenyl, or         (C₂-C₈)alkynyl;     -   each R²⁵ is independently R²⁴ wherein each R²⁴ is substituted         with 0 to 3 R²³ groups;     -   each R^(25a) is independently (C₁-C₈)alkylene,         (C₂-C₈)alkenylene, or (C₂-C₈)alkynylene any one of which said         (C₁-C₈)alkylene, (C₂-C₈)alkenylene, or (C₂-C₈)alkynylene is         substituted with 0-3 R²³ groups;     -   each W²³ is independently W²⁴ or W²⁵;     -   each W²⁴ is independently R²⁵, —C(═Y²¹)R²⁵, —C(═Y²¹)W²⁵,         —SO₂R²⁵, or —SO₂W²⁵;     -   each W²⁵ is independently carbocycle or heterocycle wherein W²⁵         is independently     -   substituted with 0 to 3 R²² groups; and     -   each Y²¹ is independently 0 or S.

TABLE 1 W¹ and W² Substituents

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

67

68

69

70

71

72

73

74

75

76

77

78

79

80

81

82

83

84

85

86

87

88

89

90

91

92

93

94

95

96

97

98

99

100

101

102

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226

227

228

229

230

231

232

233

234

235

236

237

238

239

240

241

242

243

244

245

246

247

248

249

250

251

252

253

254

255

256

257

258

103

104

105

Another embodiment of the invention is a method of treatment in a subject in need thereof, which comprises: administering a therapeutically effective amount of the compound represented by formula I to the subject; wherein the compound or its stereoisomer, salt, hydrate, solvate, or crystalline or polymorphic form thereof represented by formula III:

wherein W¹ and W² are independently selected from the group consisting of the substituents in Table 1.

Another embodiment of the invention is a method of treatment, wherein the compound, its stereoisomer, salt, hydrate, solvate, or crystalline or polymorphic form thereof, wherein the compound is selected from the group consisting of

Another embodiment of the present invention is a compound, its stereoisomer, salt, hydrate, solvate, or crystalline or polymorphic form thereof, represented by formula I:

wherein V is selected from the group consisting of phenyl and monocyclic heteroaryl, wherein (i) each said monocyclic heteroaryl contains five or six ring atoms of which 1 or 2 ring atoms are heteroatoms selected from the group consisting of N, S, and O, and the remainder of the ring atoms are carbon, and (ii) each said phenyl or monocyclic heteroaryl is unsubstituted or is substituted by one or two groups selected from halogen, trifluoromethyl, C₁-C₆ alkyl, C₁-C₆ alkoxy, and cyano.

In another embodiment of Formula I, a compound, its stereoisomer, salt, hydrate, solvate, or crystalline or polymorphic form thereof, represented by formula I:

wherein V is selected from the group consisting of the substituents in Table 2. Synthesis and general descriptions of representative substituents can be found, for instance, in U.S. Pat. No. 8,063,025, incorporated herein by reference.

TABLE 2 V Substituents

In another embodiment of Formula I, the compound, its stereoisomer, salt, hydrate, solvate, or crystalline or polymorphic form thereof, wherein the compound is selected from the group consisting of

Another embodiment of the present invention is a composition for the treatment and/or prophylaxis of any of the diseases disclosed herein said composition comprising a pharmaceutically acceptable medium selected from among an excipient, carrier, diluent, and equivalent medium and a compound, its stereoisomer, salt, hydrate, solvate, or crystalline or polymorphic form thereof, represented by formula I:

wherein V is selected from the group consisting of phenyl and monocyclic heteroaryl, wherein (i) each said monocyclic heteroaryl contains five or six ring atoms of which 1 or 2 ring atoms are heteroatoms selected from the group consisting of N, S, and O, and the remainder of the ring atoms are carbon, and (ii) each said phenyl or monocyclic heteroaryl is unsubstituted or is substituted by one or two groups selected from halogen, trifluoromethyl, C₁-C₆ alkyl, C₁-C₆ alkoxy, and cyano.

In yet another embodiment of the present invention, a composition for the treatment and/or prophylaxis of any of the diseases disclosed herein said composition comprising a pharmaceutically acceptable medium selected from among an excipient, carrier, diluent, and equivalent medium and a compound, its stereoisomer, salt, hydrate, solvate, or crystalline or polymorphic form thereof, represented by formula I:

wherein V is selected from the group consisting of the substituents in Table 2.

Another embodiment is a method of treatment in a subject in need thereof, which comprises: administering a therapeutically effective amount of the compound represented by formula I to the subject; wherein the compound or its stereoisomer, salt, hydrate, solvate, or crystalline or polymorphic form thereof represented by formula I:

wherein V is selected from the group consisting of phenyl and monocyclic heteroaryl, wherein (i) each said monocyclic heteroaryl contains five or six ring atoms of which 1 or 2 ring atoms are heteroatoms selected from the group consisting of N, S, and O, and the remainder of the ring atoms are carbon, and (ii) each said phenyl or monocyclic heteroaryl is unsubstituted or is substituted by one or two groups selected from halogen, trifluoromethyl, C₁-C₆ alkyl, C₁-C₆ alkoxy, and cyano.

Another alternative embodiment is a method of treatment in a subject in need thereof, which comprises: administering a therapeutically effective amount of the compound represented by formula I to the subject; wherein the compound or its stereoisomer, salt, hydrate, solvate, or crystalline or polymorphic form thereof represented by formula I:

wherein V is selected from the group consisting of the substituents in Table 2. In another embodiment of the current invention, the compound, its stereoisomer, salt, hydrate, solvate, or crystalline or polymorphic form thereof, wherein the compound is selected from the group consisting of

Synthetic schemes for preparing compounds of Formula I, Formula II and Formula III can be found, for instance, in the following references incorporated herein by reference. Nicotinamide Riboside and intermediates of nicotinamide riboside with protected functionalities and well established leaving groups that could be used in the synthesis of compounds of the present invention see for instance Milburn et al. (US2006/0229265) as well as Sauve et al. (U.S. Pat. No. 8,106,184). Synthetic schemes and characterization of intermediates necessary for compounds of Formula I can be found, for instance, in Heckler et al. (U.S. Pat. No. 8,063,025); Heckler et al. (U.S. application Ser. No. 12/745,419); Butler et al. (U.S. Pat. No. 8,318,682); Cho et al. (U.S. Pat. No. 8,415,308); Ross et al. (U.S. application Ser. No. 13/732,725); and Ross et al. (U.S. application Ser. No. 13/076,842). Protecting groups and/or Leaving Groups useful for synthesis of the compounds of the present invention can be found, for instance, in Ross et al. (U.S. application Ser. No. 13/076,842).

Definitions

The phrase “a” or “an” entity as used herein refers to one or more of that entity; for example, a compound refers to one or more compounds or at least one compound. As such, the terms “a” (or “an”), “one or more”, and “at least one” can be used interchangeably herein.

The terms “optional” or “optionally” as used herein means that a subsequently described event or circumstance may but need not occur, and that the description includes instances where the event or circumstance occurs and instances in which it does not. For example, “optional bond” means that the bond may or may not be present, and that the description includes single, double, or triple bonds.

The term “P*” means that the phosphorus atom is chiral and that it has a corresponding Cahn-Ingold-Prelog designation of “R” or “S” which have their accepted plain meanings.

The term “purified,” as described herein, refers to the purity of a given compound. For example, a compound is “purified” when the given compound is a major component of the composition, i.e., at least 50% w/w pure. Thus, “purified” embraces at least 50% w/w purity, at least 60% w/w purity, at least 70% purity, at least 80% purity, at least 85% purity, at least 90% purity, at least 92% purity, at least 94% purity, at least 96% purity, at least 97% purity, at least 98% purity, at least 99% purity, at least 99.5% purity, and at least 99.9% purity, wherein “substantially pure” embraces at least 97% purity, at least 98% purity, at least 99% purity, at least 99.5% purity, and at least 99.9% purity

The term “metabolite,” as described herein, refers to a compound produced in vivo after administration to a subject in need thereof.

The term “about” means that the recited numerical value is part of a range that varies within standard experimental error.

The term “substantially anhydrous” means that a substance contains at most 10% by weight of water, preferably at most 1% by weight of water, more preferably at most 0.5% by weight of water, and most preferably at most 0.1% by weight of water.

A solvent or anti-solvent (as used in reactions, crystallization, etc. or lattice and/or adsorbed solvents) includes at least one of a C₁ to C₈ alcohol, a C₂ to C₈ ether, a C₃ to C₇ ketone, a C₃ to C₇ ester, a C₁ to C₂ chlorocarbon, a C₂ to C₇ nitrile, a miscellaneous solvent, a C₅ to C₁₂ saturated hydrocarbon, and a C₆ to C₁₂ aromatic hydrocarbon.

The C₁ to C₈ alcohol refers to a straight/branched and/or cyclic/acyclic alcohol having such number of carbons. The C₁ to C₈ alcohol includes, but is not limited to, methanol, ethanol, n-propanol, isopropanol, isobutanol, hexanol, and cyclohexanol.

The C₂ to C₈ ether refers to a straight/branched and/or cyclic/acyclic ether having such number of carbons. The C₂ to C₈ ether includes, but is not limited to, dimethyl ether, diethyl ether, di-isopropyl ether, di-n-butyl ether, methyl-t-butyl ether (MTBE), tetrahydrofuran, and dioxane

The C₃ to C₇ ketone refers to a straight/branched and/or cyclic/acyclic ketone having such number of carbons. The C₃ to C₇ ketone includes, but is not limited to, acetone, methyl ethyl ketone, propanone, butanone, methyl isobutyl ketone, methyl butyl ketone, and cyclohexanone.

The C₃ to C₇ ester refers to a straight/branched and/or cyclic/acyclic ester having such number of carbons. The C₃ to C₇ ester includes, but is not limited to, ethyl acetate, propyl acetate, n-butyl acetate, etc.

The C₁ to C₂ chlorocarbon refers to a chlorocarbon having such number of carbons. The C₁ to C₂ chlorocarbon includes, but is not limited to, chloroform, methylene chloride (DCM), carbon tetrachloride, 1,2-dichloroethane, and tetrachloroethane.

A C₂ to C₇ nitrile refers to a nitrile have such number of carbons. The C₂ to C₇ nitrile includes, but is not limited to, acetonitrile, propionitrile, etc.

A miscellaneous solvent refers to a solvent commonly employed in organic chemistry, which includes, but is not limited to, diethylene glycol, diglyme (diethylene glycol dimethyl ether), 1,2-dimethoxy-ethane, dimethylformamide, dimethylsulfoxide, ethylene glycol, glycerin, hexamethylphsphoramide, hexamethylphosphorous triame, N-methyl-2-pyrrolidinone, nitromethane, pyridine, triethyl amine, and acetic acid.

The term C₅ to C₁₂ saturated hydrocarbon refers to a straight/branched and/or cyclic/acyclic hydrocarbon. The C₅ to C₁₂ saturated hydrocarbon includes, but is not limited to, n-pentane, petroleum ether (ligroine), n-hexane, n-heptane, cyclohexane, and cycloheptane.

The term C₆ to C₁₂ aromatic refers to substituted and unsubstituted hydrocarbons having a phenyl group as their backbone. Preferred hydrocarbons include benzene, xylene, toluene, chlorobenzene, o-xylene, m-xylene, p-xylene, xylenes, with toluene being more preferred.

The term “halo” or “halogen” as used herein, includes chloro, bromo, iodo and fluoro.

The term “blocking group” refers to a chemical group which exhibits the following characteristics. The “group” is derived from a “protecting compound.” Groups that are selective for primary hydroxyls over secondary hydroxyls that can be put on under conditions consistent with the stability of the phosphoramidate (pH 2-8) and impart on the resulting product substantially different physical properties allowing for an easier separation of the 3′-phosphoramidate-5′-new group product from the unreacted desired compound. The group must react selectively in good yield to give a protected substrate that is stable to the projected reactions (see Protective Groups in Organic Synthesis, 3.sup.nd ed. T. W. Greene and P. G. M. Wuts, John Wiley & Sons, New York, N.Y., 1999). Examples of groups include, but are not limited to: benzoyl, acetyl, phenyl-substituted benzoyl, tetrahydropyranyl, trityl, DMT (4,4′-dimethoxytrityl), MMT (4-monomethoxytrityl), trimethoxytrityl, pixyl (9-phenylxanthen-9-yl) group, thiopixyl (9-phenylthioxanthen-9-yl) or 9-(p-methoxyphenyl)xanthine-9-yl (MOX), etc.; C(O)-alkyl, C(O)Ph, C(O)aryl, CH₂O-alkyl, CH.sub.2O-aryl, SO₂-alkyl, SO₂-aryl, tert-butyldimethylsilyl, tert-butyldiphenylsilyl. Acetals, such as MOM or THP and the like are considered possible groups. Fluorinated compounds are also contemplated in so far that they can be attached to the compound and can be selectively removed by passing through a fluorous solid phase extraction media (FluoroFlash™). A specific example includes a fluorinated trityl analog, trityl analog 1-[4-(1H,1H,2H,2H-perfluorodecyl)phenyl)-1,1-diphenylmethanol. Other fluorinated analogs of trityl, BOC, FMOC, CBz, etc. are also contemplated. Sulfonyl chlorides like p-toluenesulfonyl chloride can react selectively on the 5′ position. Esters could be formed selectively such as acetates and benzoates. Dicarboxylic anhydrides such as succinic anhydride and its derivatives can be used to generate an ester linkage with a free carboxylic acid, such examples include, but are not limited to oxalyl, malonyl, succinyl, glutaryl, adipyl, pimelyl, superyl, azelayl, sebacyl, phthalyl, isophthalyl, terephthalyl, etc. The free carboxylic acid increases the polarity dramatically and can also be used as a handle to extract the reaction product into mildly basic aqueous phases such as sodium bicarbonate solutions. The phosphoramidate group is relatively stable in acidic media, so groups requiring acidic reaction conditions, such as, tetrahydropyranyl, could also be used.

The term “protecting group” which is derived from a “protecting compound,” has its plain and ordinary meaning, i.e., at least one protecting or blocking group is bound to at least one functional group (e.g., —OH, —NH₂, etc.) that allows chemical modification of at least one other functional group. Examples of protecting groups, include, but are not limited to, benzoyl, acetyl, phenyl-substituted benzoyl, tetrahydropyranyl, trityl, DMT (4,4′-dimethoxytrityl), MMT (4-monomethoxytrityl), trimethoxytrityl, pixyl (9-phenylxanthen-9-yl) group, thiopixyl (9-phenylthioxanthen-9-yl) or 9-(p-methoxyphenyl)xanthine-9-yl (MOX), etc.; C(O)-alkyl, C(O)Ph, C(O)aryl, C(O)O(lower alkyl), C(O)O(lower alkylene)aryl (e.g., —C(O)OCH₂Ph), C(O)Oaryl, CH₂O-alkyl, CH₂O-aryl, SO₂-alkyl, SO₂-aryl, a protecting group comprising at least one silicon atom, such as, tert-butyldimethylsilyl, tert-butyldiphenylsilyl, Si(lower alkyl)₂OSi(lower alkyl)₂OH (such as, —Si(^(i)Pr)₂OSi(^(i)Pr)₂OH.

The term “protecting compound,” as used herein and unless otherwise defined, refers to a compound that contains a “protecting group” and that is capable of reacting with a compound that contains functional groups that are capable of being protected.

The term “leaving group”, as used herein, has the same meaning to the skilled artisan (Advanced Organic Chemistry: reactions, mechanisms and structure—Fourth Edition by Jerry March, John Wiley and Sons Ed.; 1992 pages 351-357) and represents a group which is part of and attached to a substrate molecule; in a reaction where the substrate molecule undergoes a displacement reaction (with for example a nucleophile), the leaving group is then displaced. Examples of leaving groups include, but are not limited to: halogen (F, Cl, Br, and I), preferably Cl, Br, or I; tosylate, mesylate, triflate, acetate, camphorsulfonate, aryloxide, and aryloxide substituted with at least one electron withdrawing group (e.g., p-nitrophenoxide, 2-chlorophenoxide, 4-chlorophenoxide, 2,4-dinitrophenoxide, pentafluorophenoxide, etc.), etc. The term “electron withdrawing group” is accorded its plain meaning here. Examples of electron withdrawing groups include, but are not limited to, a halogen, —NO₂, —C(O)(lower alkyl), —C(O)(aryl), —C(O)O(lower alkyl), —C(O)O(aryl), etc.

The term “basic reagent”, as used herein, means a compound that is capable of deprotonating a hydroxyl group. Examples of basic reagents include, but are not limited to, a (lower alk)oxide ((lower alkyl)OM) in combination with an alcoholic solvent, where (lower alk)oxides include, but are not limited to, MeO⁻, EtO⁻, ^(n)PrO⁻, ^(t)BuO⁻, ^(i)AmO⁻-(iso-amyloxide), etc., and where M is an alkali metal cation, such as Li⁺, Na⁺, K⁺, etc. Alcoholic solvents include (lower alkyl)OH, such as, for example, MeOH, EtOH, ^(n)PrOH, ^(i)PrOH, ^(t)BuOH, ^(i)AmOH, etc. Non-alkoxy bases can also be used such as sodium hydride, sodium hexamethyldisilazane, lithium hexamethyldisilazane, lithium diisopropylamide, calcium hydride, sodium carbonate, potassium carbonate, cesium carbonate, DBU, DBN, Grignard reagents, such as (lower alkyl)Mg(halogen), which include but are not limited to MeMgCl, MeMgBr, ^(t)BuMgCl, ^(t)BuMgBr, etc.

The term “base” embraces the term “basic reagent” and is meant to be a compound that is capable of deprotonating a proton containing compound, i.e., a Bronsted base. In addition to the examples recited above, further examples of a base include, but are not limited to pyridine, collidine, 2,6-(loweralkyl)-pyridine, dimethyl-aniline, imidazole, N-methyl-imidazole, pyrazole, N-methyl-pyrazole, triethylamine, di-isopropylethylamine, etc.

The term “electron withdrawing group” is accorded its plain meaning Examples of electron withdrawing groups include, but are not limited to, a halogen (F, C₁, Br, or I), —NO₂, —C(O)(lower alkyl), —C(O)(aryl), —C(O)O(lower alkyl), —C(O)O(aryl), etc.

The term “salts,” as described herein, refers to a compound comprising a cation and an anion, which can produced by the protonation of a proton-accepting moiety and/or deprotonation of a proton-donating moiety. It should be noted that protonation of the proton-accepting moiety results in the formation of a cationic species in which the charge is balanced by the presence of a physiological anion, whereas deprotonation of the proton-donating moiety results in the formation of an anionic species in which the charge is balanced by the presence of a physiological cation.

The phrase “pharmaceutically acceptable salt” means a salt that is pharmaceutically acceptable. Examples of pharmaceutically acceptable salts include, but are not limited to: (1) acid addition salts, formed with inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, and the like; or formed with organic acids such as glycolic acid, pyruvic acid, lactic acid, malonic acid, malic acid, maleic acid, fumaric acid, tartaric acid, citric acid, 3-(4-hydroxybenzoyl)benzoic acid, cinnamic acid, mandelic acid, methanesulfonic acid, ethanesulfonic acid, 1,2-ethane-disulfonic acid, 2-hydroxyethanesulfonic acid, benzenesulfonic acid, 4-chlorobenzenesulfonic acid, 2-naphthalenesulfonic acid, 4-toluenesulfonic acid, camphorsulfonic acid, lauryl sulfuric acid, gluconic acid, glutamic acid, salicylic acid, muconic acid, and the like or (2) basic addition salts formed with the conjugate bases of any of the inorganic acids listed above, wherein the conjugate bases comprise a cationic component selected from among Na⁺, K⁺, Mg²⁺, Ca²⁺, NH_(g)R^(′″4−)g⁺, in which R′″ is a C₁₋₃ alkyl and g is a number selected from among 0, 1, 2, 3, or 4. It should be understood that all references to pharmaceutically acceptable salts include solvent addition forms (solvates) or crystal forms (polymorphs) as defined herein, of the same acid addition salt.

The term “alkyl” refers to an unbranched or branched chain, saturated, monovalent hydrocarbon residue containing 1 to 30 carbon atoms. The term “C.sub.1-M alkyl” refers to an alkyl comprising 1 to M carbon atoms, where M is an integer having the following values: 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30. The term “C₁₋₄ alkyl” refers to an alkyl containing 1 to 4 carbon atoms. The term “lower alkyl” denotes a straight or branched chain hydrocarbon residue comprising 1 to 6 carbon atoms. “C₁₋₂₀ alkyl” as used herein refers to an alkyl comprising 1 to 20 carbon atoms. “C₁₋₁₀ alkyl” as used herein refers to an alkyl comprising 1 to 10 carbons. Examples of alkyl groups include, but are not limited to, lower alkyl groups include methyl, ethyl, propyl, propyl, n-butyl, i-butyl, t-butyl or pentyl, isopentyl, neopentyl, hexyl, heptyl, and octyl. The term (ar)alkyl or (heteroaryl)alkyl indicate the alkyl group is optionally substituted by an aryl or a heteroaryl group respectively.

The term “alkenyl” refers to an unsubstituted hydrocarbon chain radical having from 2 to 10 carbon atoms having one or two olefinic double bonds, preferably one olefinic double bond. The term “C_(2-N) alkenyl” refers to an alkenyl comprising 2 to N carbon atoms, where N is an integer having the following values: 3, 4, 5, 6, 7, 8, 9, or 10. The term “C₂₋₁₀ alkenyl” refers to an alkenyl comprising 2 to 10 carbon atoms. The term “C₂₋₄ alkenyl” refers to an alkenyl comprising 2 to 4 carbon atoms. Examples include, but are not limited to, vinyl, 1-propenyl, 2-propenyl (allyl) or 2-butenyl (crotyl).

The term “aryl,” as used herein, and unless otherwise specified, refers to substituted or unsubstituted phenyl (Ph), biphenyl, or naphthyl, preferably the term aryl refers to substituted or unsubstituted phenyl. The aryl group can be substituted with one or more moieties selected from among hydroxyl, F, Cl, Br, I, amino, alkylamino, arylamino, alkoxy, aryloxy, nitro, cyano, sulfonic acid, sulfate, phosphonic acid, phosphate, and phosphonate, either unprotected, or protected as necessary, as known to those skilled in the art, for example, as taught in T. W. Greene and P. G. M. Wuts, Protective Groups in Organic Synthesis, 3rd ed., John Wiley & Sons, 1999.

The term “aryloxide,” as used herein, and unless otherwise specified, refers to substituted or unsubstituted phenoxide (PhO—), p-phenyl-phenoxide (p-Ph-PhO—), or naphthoxide, preferably the term aryloxide refers to substituted or unsubstituted phenoxide. The aryloxide group can be substituted with one or more moieties selected from among hydroxyl, F, Cl, Br, I, —C(O)(lower alkyl), —C(O)O(lower alkyl), amino, alkylamino, arylamino, alkoxy, aryloxy, nitro, cyano, sulfonic acid, sulfate, phosphonic acid, phosphate, and phosphonate, either unprotected, or protected as necessary, as known to those skilled in the art, for example, as taught in T. W. Greene and P. G. M. Wuts, Protective Groups in Organic Synthesis, 3rd ed., John Wiley & Sons, 1999.

The term “preparation” or “dosage form” is intended to include both solid and liquid formulations of the active compound and one skilled in the art will appreciate that an active ingredient can exist in different preparations depending on the desired dose and pharmacokinetic parameters.

The term “excipient” as used herein refers to a compound that is used to prepare a pharmaceutical composition, and is generally safe, non-toxic and neither biologically nor otherwise undesirable, and includes excipients that are acceptable for veterinary use as well as human pharmaceutical use.

“Nicotinamide”, which corresponds to the following structure,

is one of the two principal forms of the B-complex vitamin niacin. The other principal form of niacin is nicotinic acid; nicotinamide, rather than nicotinic acid, however, is the major substrate for nicotinamide adenine dinucleotide (NAD) biosynthesis in mammals, as discussed in detail herein. Nicotinamide, in addition to being known as niacinamide, is also known as 3-pyridinecarboxamide, pyridine-3-carboxamide, nicotinic acid amide, vitamin B3, and vitamin PP. Nicotinamide has a molecular formula of C₆H₆N₂O and its molecular weight is 122.13 Daltons. Nicotinamide is commercially available from a variety of sources.

“Nicotinamide Riboside” (NR), which corresponds to the following structure,

is characterized and a synthesized as described in, for instance, U.S. Pat. No. 8,106,184.

“Nicotinamide Mononucleotide” (NMN), which corresponds to the following structure,

is produced from nicotinamide in the NAD biosynthesis pathway, a reaction that is catalyzed by Nampt. NMN is further converted to NAD in the NAD biosynthesis pathway, a reaction that is catalyzed by NMNAT. Nicotinamide mononucleotide (NMN) has a molecular formula of C₁₁H₁₅N₂O₈P and a molecular weight of 334.22. Nicotinamide mononucleotide (NMN) is commercially available from such sources as Sigma-Aldrich (St. Louis, Mo.).

“Nicotinamide Adenine Dinucleotide” (NAD), which corresponds to the following structure,

is produced from the conversion of nicotinamide to NMN, which is catalyzed by Nampt, and the subsequent conversion of NMN to NAD, which is catalyzed by NMNAT. Nicotinamide adenine dinucleotide (NAD) has a molecular formula of C₂₁H₂₇N₇O₁₄P₂ and a molecular weight of 663.43. Nicotinamide adenine dinucleotide (NAD) is commercially available from such sources as Sigma-Aldrich (St. Louis, Mo.).

Pharmaceutical Compositions

In certain embodiments the instant invention relates to a composition, e.g., a pharmaceutical composition, containing at least one agent or nicotinamide mononucleotide, analog and derivatives thereof, described herein together with a pharmaceutically acceptable carrier. In one embodiment, the composition includes a combination of multiple (e.g., two or more) agents of the invention.

As described in detail below, the pharmaceutical compositions of the present invention may be specially formulated for administration in solid or liquid form, including those adapted for the following: (1) oral administration, for example, drenches (aqueous or non-aqueous solutions or suspensions), tablets, e.g., those targeted for buccal, sublingual, and systemic absorption, boluses, powders, granules, pastes for application to the tongue; (2) parenteral administration, for example, by subcutaneous, intramuscular, intravenous or epidural injection as, for example, a sterile solution or suspension, or sustained-release formulation; or (3) in a drink form, or sachet, that is mixed prior to ingestion.

Methods of preparing these formulations or compositions include the step of bringing into association an agent described herein with the carrier and, optionally, one or more accessory ingredients. In general, the formulations are prepared by uniformly and intimately bringing into association an agent described herein with liquid carriers, or finely divided solid carriers, or both, and then, if necessary, shaping the product.

Pharmaceutical compositions of this invention suitable for parenteral administration comprise one or more agents described herein in combination with one or more pharmaceutically-acceptable sterile isotonic aqueous or nonaqueous solutions, dispersions, suspensions or emulsions, or sterile powders which may be reconstituted into sterile injectable solutions or dispersions just prior to use, which may contain sugars, alcohols, antioxidants, buffers, bacteriostats, solutes which render the formulation isotonic with the blood of the intended recipient or suspending or thickening agents.

Examples of suitable aqueous and nonaqueous carriers which may be employed in the pharmaceutical compositions of the invention include water, ethanol, polyols (such as glycerol, propylene glycol, polyethylene glycol, and the like), and suitable mixtures thereof, vegetable oils, such as olive oil, and injectable organic esters, such as ethyl oleate. Proper fluidity can be maintained, for example, by the use of coating materials, such as lecithin, by the maintenance of the required particle size in the case of dispersions, and by the use of surfactants.

Regardless of the route of administration selected, the agents of the present invention, which may be used in a suitable hydrated form, and/or the pharmaceutical compositions of the present invention, are formulated into pharmaceutically-acceptable dosage forms by conventional methods known to those of skill in the art.

4. Therapeutic Methods and Uses

Providede herein are methods of recovering from, treating, and preventing cancer, aging, cell death, radiation damage, radiation exposure, chemotherapy-induced damage, cellular senescence, among others, improving DNA repair, cell proliferation, cell survival, among others, and increasing the life span of a cell or protect it against certain stresses, among others by providing nicotinamide mononucleotides, encompassing analogs and derivatives thereof (e.g., NAD+) as set forth in sections 3 and 4 above. In some embodiments, the methods involve increasing the level or activity of nicotinamide dinucleotides (e.g., NAD+, NMN; NAD+ precursor pathways, such as a protein selected from the group consisting of NPT1, PNC1, NMA1 and NMA2; or NAD+ biosynthesis, such as enzymes selected from NMNAT-1, -2, and/or -3 or NAMPT).

The level of protein can be increased in a cell, e.g., by introducing into the cell a nucleic acid encoding the protein operably linked to a transcriptional regulatory sequence directing the expression of the protein in the cell. Methods for expressing nucleic acids in cells and appropriate transcriptional regulatory elements for doing so are well known in the art. Alternatively, a protein can be introduced into a cell, usually in the presence of a vector facilitating the entry of the protein into the cells, e.g., liposomes. Proteins can also be linked to transcytosis peptides for that purpose. Yet in other methods, an agent that stimulates expression of the endogenous gene is contacted with a cell. Such agents can be identified as further described herein.

It will be apparent to a person of skill in the art that a full length protein or nucleic acid encoding such or a portion thereof can be used according to the methods described herein. A portion of a protein is preferably a biologically active portion thereof. Portions that are biologically active can be identified according to methods known in the art and using an assay that can monitor the activity of the particular protein. Assays for determining the activity of any of the aforementioned protein are described, e.g., in Pescanglini et al. (1994) Clin. Chim. Acta 229: 15-25 and Sestini et al. (2000) Archives of Biochem. Biophys. 379:277. Alternatively, the activity of such a protein can be tested in an assay in which the life span of a cell is determined. For example, a cell is transfected with a nucleic acid comprising one or more copies of a sequence encoding a portion of an NPT1, PNC1, NMA1, NMA2, NMNAT-1, -2, and/or -3, or NAMPT protein or a control nucleic acid, and the life span of the cells is compared. A longer life span of a cell transfected with a portion of one of the proteins indicates that the portion of the protein is a biologically active portion. Assays for determining the life span of a cell are known in the art and are also further described herein. In particular, assays for determining the life span of a mammalian cell can be conducted as described, e.g., in Cell Growth, Differentiation and Senescence: A Practical Approach. George P. Studzinski (ed.). Instead of measuring the life span, one can also measure the resistance of a transfected cell to certain stresses, e.g., heatshock, for determining whether a portion of a protein is a biologically active portion. Methods for measuring resistance to certain stresses are known in the art and are also further described herein. In particular, assays for determining the resistance of a mammalian cell to heatshock can be conducted as described, e.g., in Bunelli et al. (1999) Exp. Cell Res. 262: 20.

In addition to portions of NPT1, PNC1, NMA1, NMA2, NMNAT-1, -2, and/or -3, or NAMPT proteins, other variants, such as proteins containing a deletion, insertion or addition of one or more amino acids can be used, provided that the protein is biologically active. Exemplary amino acid changes include conservative amino acid substitutions. Other changes include substitutions for non-naturally occurring amino acids. Proteins encoded by nucleic acids that hybridize to a nucleic acid encoding NPT1, PNC1, NMA1, NMA2, NMNAT-1, -2, and/or -3, or NAMPT under high or medium stringency conditions and which are biologically active can also be used. For example, nucleic acids that hybridize under high stringency conditions of 0.2 to 1×SSC at 65° C. followed by a wash at 0.2×SSC at 65° C. to a gene encoding NPT1, PNC1, NMA1, NMA2, NMNAT-1, -2, and/or -3, or NAMPT can be used. Nucleic acids that hybridize under low stringency conditions of 6×SSC at room temperature followed by a wash at 2×SSC at room temperature to a gene encoding NPT1, PNC1, NMA1, NMA2, NMNAT-1, -2, and/or -3, or NAMPT can be used. Other Other hybridization conditions include 3×SSC at 40 or 50° C., followed by a wash in 1 or 2×SSC at 20, 30, 40, 50, 60, or 65° C. Hybridizations can be conducted in the presence of formaldehyde, e.g., 10%, 20%, 30% 40% or 50%, which further increases the stringency of hybridization. Theory and practice of nucleic acid hybridization is described, e.g., in S. Agrawal (ed.) Methods in Molecular Biology, volume 20; and Tijssen (1993) Laboratory Techniques in biochemistry and molecular biology-hybridization with nucleic acid probes, e.g., part I chapter 2 “Overview of principles of hybridization and the strategy of nucleic acid probe assays,” Elsevier, New York provide a basic guide to nucleic acid hybridization.

Exemplary proteins may have at least about 50%, 70%, 80%, 90%, preferably at least about 95%, even more preferably at least about 98% and most preferably at least 99% homology or identity with a wild-type NPT1, PNC1, NMA1, NMA2, NMNAT-1, -2, and/or -3, or NAMPT protein or a domain thereof, e.g., the catalytic domain. Other exemplary proteins may be encoded by a nucleic acid that is at least about 90%, preferably at least about 95%, even more preferably at least about 98% and most preferably at least 99% homology or identity with a wild-type NPT1, PNC1, NMA1, NMA2, NMNAT-1, -2, and/or -3, or NAMPT nucleic acid, e.g., those described herein.

In other embodiments proteins are fusion proteins, e.g., proteins fused to a transcytosis peptide. Fusion proteins may also comprise a heterologous peptide that can be used to purify the protein and/or to detect it.

In other embodiments, non-naturally occurring protein variants are used. Such variants can be peptidomimetics.

In yet other embodiments, the activity of one or more proteins selected from the group consisting of NPT1, PNC1, NMA1, NMA2, NMNAT-1, -2, and/or -3 or NAMPT is enhanced or increased. This can be achieved, e.g., by contacting a cell with a compound that increases the activity, e.g., enzymatic activity, of one of these proteins. Assays for identifying such compounds are further described herein.

Any means for the introduction of polynucleotides into mammals, human or non-human, or cells thereof may be adapted to the practice of this invention for the delivery of the various constructs of the invention into the intended recipient. In one embodiment of the invention, the DNA constructs are delivered to cells by transfection, i.e., by delivery of “naked” DNA or in a complex with a colloidal dispersion system. A colloidal system includes macromolecule complexes, nanocapsules, microspheres, beads, and lipid-based systems including oil-in-water emulsions, micelles, mixed micelles, and liposomes. The preferred colloidal system of this invention is a lipid-complexed or liposome-formulated DNA. In the former approach, prior to formulation of DNA, e.g., with lipid, a plasmid containing a transgene bearing the desired DNA constructs may first be experimentally optimized for expression (e.g., inclusion of an intron in the 5′ untranslated region and elimination of unnecessary sequences (Felgner, et al., Ann NY Acad Sci 126-139, 1995). Formulation of DNA, e.g. with various lipid or liposome materials, may then be effected using known methods and materials and delivered to the recipient mammal. See, e.g., Canonico et al, Am J Respir Cell Mol Biol 10:24-29, 1994; Tsan et al, Am J Physiol 268; Alton et al., Nat Genet. 5:135-142, 1993 and U.S. Pat. No. 5,679,647 by Carson et al.

The expression of a protein, e.g., a protein selected from the group consisting of NPT1, PNC1, NMA1, NMA2, NMNAT-1, -2, and/or -3, or NAMPT or a biologically active variant thereof in cells of a subject to whom, e.g., a nucleic acid encoding the protein was administered, can be determined, e.g., by obtaining a sample of the cells of the patient and determining the level of the protein in the sample, relative to a control sample.

In another embodiment, a protein or biologically active variant thereof, is administered to the subject such that it reaches the target cells, and traverses the cellular membrane. Polypeptides can be synthesized in prokaryotes or eukaryotes or cells thereof and purified according to methods known in the art. For example, recombinant polypeptides can be synthesized in human cells, mouse cells, rat cells, insect cells, yeast cells, and plant cells. Polypeptides can also be synthesized in cell free extracts, e.g., reticulocyte lysates or wheat germ extracts. Purification of proteins can be done by various methods, e.g., chromatographic methods (see, e.g., Robert K Scopes Protein Purification: Principles and Practice Third Ed. Springer-Verlag, N.Y. 1994). In one embodiment, the polypeptide is produced as a fusion polypeptide comprising an epitope tag consisting of about six consecutive histidine residues. The fusion polypeptide can then be purified on a column. By inserting a protease site between the tag and the polypeptide, the tag can be removed after purification of the peptide on the N⁺⁺ column. These methods are well known in the art and commercial vectors and affinity matrices are commercially available.

Administration of polypeptides can be done by mixing them with liposomes, as described above. The surface of the liposomes can be modified by adding molecules that will target the liposome to the desired physiological location.

In one embodiment, a protein is modified so that its rate of traversing the cellular membrane is increased. For example, the polypeptide can be fused to a second peptide which promotes “transcytosis,” e.g., uptake of the peptide by cells. In one embodiment, the peptide is a portion of the HIV transactivator (TAT) protein, such as the fragment corresponding to residues 37-62 or 48-60 of TAT, portions which are rapidly taken up by cell in vitro (Green and Loewenstein, (1989) Cell 55:1179-1188). In another embodiment, the internalizing peptide is derived from the Drosophila antennapedia protein, or homologs thereof. The 60 amino acid long homeodomain of the homeo-protein antennapedia has been demonstrated to translocate through biological membranes and can facilitate the translocation of heterologous polypeptides to which it is couples. Thus, polypeptides can be fused to a peptide consisting of about amino acids 42-58 of Drosophila antennapedia or shorter fragments for transcytosis. See for example Derossi et al. (1996) J Biol Chem 271:18188-18193; Derossi et al. (1994) J Biol Chem 269:10444-10450; and Perez et al. (1992)J Cell Sci 102:717-722.

In another embodiment, the amount of nicotinamide is decreased in a cell. This can be achieved, e.g., by inhibiting the expression of genes of the NAD+ salvage pathway or other pathway that produce nicotinamide. Inhibition of the genes can be conducted, e.g., as further described herein, such as by performing RNAi on the NAD+ salvage pathway genes that produce nicotinamide. One can also inhibit genes that are involved in the de novo synthesis of nicotinamide. For example, nicotinamide levels in cells can be regulated by regulating the level or activity of poly(adenosine diphosphate-ribose) polymerase-1 (PARP). In particular, nicotinamide levels can be reduced by reducing the level or activity of PARP, since this enzyme generates nicotinamide. Nicotinamide levels may also be decreased in cells by reducing the level or activity of glycohydrolases (e.g., human CD38, an ectoenzyme that is expressed on the surface of immune cells, such as neutrophils; gi:4502665 and GenBank Accession No. NP_001766), which cleave NAD to nicotinamide.

Nicotinamide levels may also be decreased by inhibiting the de novo nicotinamide synthesis pathway. Genes involved in this pathway include the BNA genes in S. cerevisiae (BNA1-6). Alternatively, poly(adenosine diphosphate-ribose) polymerase (PARP) family members, e.g., PARP-1 and PARPv and tankyrase can also be inhibited to decrease nicotinamide levels.

It is also possible to reduce the level or activity of nicotinamide transporters to reduce the level of nicotinamide that is imported into cells. For example, in yeast, nicotinic acid is transported by the Tna1 (nicotinate/nicotinamide mononucleotide transport) protein. Human homologues of yeast TNA1 have the following GenBank Accession numbers: gi:9719374 and AAF97769; gi:6912666 and NP_036566; gi:18676562 and AB84933; gi:12718201 and CAC28600; gi:19263934 and AAH25312; gi:9966811 and NP_065079; and gi:22761334 and BAC11546. Other nucleoside transporters that can be modulated include bacterial and fly nucleoside transporter and the following human genes that are homologous thereto: gi:8923160 and NP_060164; gi:14336678 and AAK61212; gi: 22749231 and NP_689812; and gi: 18603939 and XP_091525.

Alternatively, nicotinamide levels can be decreased or nicotinamide inactivated, e.g., by stimulating the activity or increase the level of enzymes that metabolize, degrade or inhibit nicotinamide, e.g., nicotinamide N-methyl transferase, also referred to as nicotinamide methyltransferase (NNMT; EC 2.1.1.1; CAS registry number 9029-74-7). This enzyme catalyzes the reaction S-adenosyl-L-methionine+ nicotinamide=S-adenosyl-L-homocysteine+1-methylnicotinamide and promotes excretion of nicotinamide from the cell (see also, Cantoni (1951) J Biol. Chem. 203-216). The human enzyme is referred to as NNMT and its complete sequence can be found at GenBank Accession number U08021 and as SEQ ID NO: 9 for the nucleotide sequence and SEQ ID NO: 10 for the protein (Aksoy et al. (1994) J Biol. Chem. 269:14835). The yeast version of this enzyme is referred to as NNT1 (also referred to as YLR258w).

Yet another enzyme that metabolizes nicotinamide and thereby reduces the level of nicotinamide is nicotinamide phosphribosyltransferase (NAMPRT; E.C.2.4.2.12). The human gene is also referred to as pre-B-cell colony enhancing factor (PBEF), and its sequence is available under GenBank Accession numbers NP_005737; NM_005746; AAH20691; and BC020691. The nucleotide and amino acid sequences of human NAMPRT (BC020691) are set forth as SEQ ID NOs: 11 and 12, respectively. In yeast and human cells, the level of NPT1 or human homolog thereof, respectively, can be increased to reduce nicotinamide levels.

Another enzyme that metabolizes nicotinamide and may thereby modulate, e.g., reduce, the level of nicotinamide is nicotinamide mononucleotide (NMN) adenylyltransferase in human cells. The human enzyme is referred to as NMNAT-1 (E.C.2.7.7.18). The following GenBank Accession numbers are provided for the human enzyme: NP_073624; NM_022787; AAL76934; AF459819; and NP_073624; AF314163. A variant of this gene is NMNAT-2 (KIAA0479), the human version of which can be found under GenBank Accession numbers NP_055854 and NM_015039 (Raffaelli et al. (2002) Biochem Biophys Res Commun 297:835). In yeast cells, the equivalent enzymes in the NAD+ salvage pathway are nicotinate mononucleotide adenyltransferase 1 and 2 (NMA1 and NMA2, respectively) (E.C. 2.7.7.1). Another variant is NMNAT-3, the human version of which can be found under GenBank Accession numbers NP_001186976.1, NP_001307439.1, NP_001307440.1, NP_001307441.1, NP_001307442.1, NP_835471.1. In some embodiments of the present invention, the NMNAT-2 and NMNAT-3 are nuclear targeted.

Yet another enzyme that may be increased to decrease nicotinamide levels is phosphoribosyl pyrophosphate (PRPP) synthase (PRPS), which converts ribose 5-phosphate to PRPP, the substrate of NPT1. There are several related enzymes, having the following GenBank Accession numbers: gi:4506127 and NP_002755 (Prps1); gi:4506129 and NP_002756 (Prps2); gi:20539448; gi:4506133 and NP_002758 (Prps associated protein 2); gi:24418495 and Q14558 (Prps associated protein 1); gi:17644236 and CAD18892; gi:2160401 and BAA05675 (Prps isoform 1); and gi:2160402 and BAA05676 (Prps isoform 2).

Reducing nicotinamide levels in cells may also provide other advantages, such as stimulating DNA break repair. Indeed, PARP is regulated by nicotinamide (nicotinamide negatively regulates PARP). Thus, regulating the level of nicotinamide in cells, e.g., as further described herein, will regulate the activity of PARP. Accordingly, since PARP is involved in numerous cellular functions, such as DNA break repair, telomere-length regulation, and histone modification, modulating nicotinamide levels will modulate these activities. For example, reducing nicotinamide levels in cells will increase the activity of PARP and thereby further enhance the DNA break repair mechanism of cells.

In addition to applying the methods of the invention in eukaryotic cells, such as mammalian cells and yeast cells, the methods can also be applied to plant cells. Accordingly, the invention also provides methods for extending the life span of plants and plant cells and for rendering the plant and plant cells more resistant to stress, e.g., excessive salt conditions. This can be achieved, e.g., by modulating the level or activity of proteins in the plant cells that are essentially homologous to the proteins described herein in the yeast and mammalian systems as increasing the life span and/or the stress resistance of cells. Alternatively, the level of nicotinamide in plant cells can be reduced, in particular, as described herein for modulating their level in other eukaryotic cells. Nucleic acids can be introduced into plant cells according to methods known in the art.

For example, the following are genes form Arabidopsis thalainia that are homologous to the genes described above that can be modulated to modulate the pathways leading to NAD+ or reduction of nicotinamide levels in cells. Homologues of yeast PNC1: gi 18401044 NP_566539.1 (a putative hydrolase); gi 15237256 NP_1977131; and gi 15237258 NP_197714.1. Homologues of yeast NPT1: gi 2026021 AAM13003.1; gi 15234571 NP_195412.1; gi 25054896 AAN71931.1; and gi 15227832 NP_179923.1. Homologues of yeast NMA1/2: gi 22327861 NP_200392.2 and gi 9758615 BAB09248.1. Homologues of yeast NNT1 (YL285W): gi 20197178 AAC14529; gi 22325900 NP_565619.2; gi 15219438 NP_177475.1 (a Tumor related Protein); gi 12324311 AA652120.1; gi:22330409 NP_683465; gi:15240506 NP_199767; gi 8778835 AAF79834.1; and gi 15231011 NP_188637. Homologue of human NNMT: gi 15238203 NP_196623. Homologue of yeast QNS1 (gene downstream of NMA1/2 in the NAD+ salvage pathway): gi:15221990 NP_175906. Homologues of yeast BNA6: gi:18379203 NP_565259 and gi:21555686 AAM63914.

In some embodiments, the invention relates to the use of a nicotinamide mononucleotide based derivative to prevent adverse effects and protect cells from toxicity. Toxicity may be an adverse effect of radiation or external chemicals on the cells of the body. Examples of toxins are pharmaceuticals, drugs of abuse, and radiation, such as UV or X-ray light. Both radiative and chemical toxins have the potential to damage biological molecules such as DNA. This damage typically occurs by chemical reaction of the exogenous agent or its metabolites with biological molecules, or indirectly through stimulated production of reactive oxygen species (eg, superoxide, peroxides, hydroxyl radicals). Repair systems in the cell excise and repair damage caused by toxins.

Enzymes that use NAD+ play a part in the DNA repair process. Specifically, the poly(ADP-ribose) polymerases (PARPs), particularly PARP-1, are activated by DNA strand breaks and affect DNA repair. The PARPs consume NAD+ as an adenosine diphosphate ribose (ADPR) donor and synthesize poly(ADP-ribose) onto nuclear proteins such as histones and PARP itself. Although PARP activities facilitate DNA repair, overactivation of PARP can cause significant depletion of cellular NAD+, leading to cellular necrosis. The apparent sensitivity of NAD+ metabolism to genotoxicity has led to pharmacological investigations into the inhibition of PARP as a means to improve cell survival. Numerous reports have shown that PARP inhibition increases NAD+ concentrations in cells subject to genotoxicity, with a resulting decrease in cellular necrosis. Nevertheless, cell death from toxicity still occurs, presumably because cells are able to complete apoptotic pathways that are activated by genotoxicity. Thus, significant cell death is still a consequence of DNA/macromolecule damage, even with inhibition of PARP. This consequence suggests that improvement of NAD+ metabolism in genotoxicity can be partially effective in improving cell survival but that other players that modulate apoptotic sensitivity, such as sirtuins, may also play important roles in cell responses to genotoxins.

Physiological and biochemical mechanisms that determine the effects of chemical and radiation toxicity in tissues are complex, and evidence indicates that NAD+ metabolism is an important player in cell stress response pathways. For example, upregulation of NAD+ metabolism, via nicotinamide/nicotinic acid mononucleotide (NMNAT-1, -2, and/or -3) overexpression, has been shown to protect against neuron axonal degeneration, and nicotinamide used pharmacologically has been recently shown to provide neuron protection in a model of fetal alcohol syndrome and fetal ischemia. Such protective effects could be attributable to upregulated NAD+ biosynthesis, which increases the available NAD+ pool subject to depletion during genotoxic stress. This depletion of NAD+ is mediated by PARP enzymes, which are activated by DNA damage and can deplete cellular NAD+, leading to necrotic death. Another mechanism of enhanced cell protection that could act in concert with upregulated NAD+ biosynthesis is the activation of cell protection transcriptional programs regulated by sirtuin enzymes.

In one embodiment, the invention provides a method extending the lifespan of a cell, extending the proliferative capacity of a cell, slowing aging of a cell, promoting the survival of a cell, delaying cellular senescence in a cell, mimicking the effects of calorie restriction, increasing the resistance of a cell to stress, or preventing apoptosis of a cell, by contacting the cell with a nicotinamide mononucleotide based derivative compound. In an exemplary embodiment, the methods comprise contacting the cell with a nicotinamide mononucleotide based derivative to thereby bidn and modulate the activity of a biologically active polypeptide comprising a Nudix homology domain (NHD), or fragment thereof, or a nucleic acid encoding same.

The methods described herein may be used to increase the amount of time that cells, particularly primary cells (i.e., cells obtained from an organism, e.g., a human), may be kept alive in a cell culture. Embryonic stem (ES) cells and pluripotent cells, and cells differentiated therefrom, may also be treated with nicotinamide mononucleotide based or derivative compound to keep the cells, or progeny thereof, in culture for longer periods of time. Such cells can also be used for transplantation into a subject, e.g., after ex vivo modification.

In one embodiment, cells that are intended to be preserved for long periods of time may be treated with a nicotinamide mononucleotide based derivative compound. The cells may be in suspension (e.g., blood cells, serum, biological growth media, etc.) or in tissues or organs. For example, blood collected from an individual for purposes of transfusion may be treated with a nicotinamide mononucleotide based derivative compound to preserve the blood cells for longer periods of time. Additionally, blood to be used for forensic purposes may also be preserved using a nicotinamide mononucleotide based derivative compound. Other cells that may be treated to extend their lifespan or protect against apoptosis include cells for consumption, e.g., cells from non-human mammals (such as meat) or plant cells (such as vegetables).

Nicotinamide mononucleotide based derivative compounds may also be applied during developmental and growth phases in mammals, plants, insects or microorganisms, in order to, e.g., alter, retard or accelerate the developmental and/or growth process.

In another embodiment, a nicotinamide mononucleotide based derivative compounds may be used to treat cells useful for transplantation or cell therapy, including, for example, solid tissue grafts, organ transplants, cell suspensions, stem cells, bone marrow cells, etc. The cells or tissue may be an autograft, an allograft, a syngraft or a xenograft. The cells or tissue may be treated with the nicotinamide mononucleotide based derivative compound prior to administration/implantation, concurrently with administration/implantation, and/or post administration/implantation into a subject. The cells or tissue may be treated prior to removal of the cells from the donor individual, ex vivo after removal of the cells or tissue from the donor individual, or post implantation into the recipient. For example, the donor or recipient individual may be treated systemically with a nicotinamide mononucleotide based derivative compound or may have a subset of cells/tissue treated locally with a nicotinamide mononucleotide based derivative compound. In certain embodiments, the cells or tissue (or donor/recipient individuals) may additionally be treated with another therapeutic agent useful for prolonging graft survival, such as, for example, an immunosuppressive agent, a cytokine, an angiogenic factor, etc.

In yet other embodiments, cells may be treated with a nicotinamide mononucleotide based derivative compound that increases the level of NAD+ in vivo, e.g., to increase their lifespan or prevent apoptosis. For example, skin can be protected from aging (e.g., developing wrinkles, loss of elasticity, etc.) by treating skin or epithelial cells with a nicotinamide mononucleotide based derivative compound or cream that increases the level intracellular NAD+. In an exemplary embodiment, skin is contacted with a cream, pharmaceutical or cosmetic composition comprising a nicotinamide mononucleotide based derivative compound that increases the level of intracellular NAD+. Exemplary skin afflictions or skin conditions that may be treated in accordance with the methods described herein include disorders or diseases associated with or caused by inflammation, sun damage or natural aging. For example, the compositions find utility for sunburn prevention, recovery from sunburn, and in the prevention or treatment of contact dermatitis (including irritant contact dermatitis and allergic contact dermatitis), atopic dermatitis (also known as allergic eczema), actinic keratosis, keratinization disorders (including eczema), epidermolysis bullosa diseases (including penfigus), exfoliative dermatitis, seborrheic dermatitis, erythemas (including erythema multiforme and erythema nodosum), damage caused by the sun or other light sources, discoid lupus erythematosus, dermatomyositis, psoriasis, skin cancer and the effects of natural aging. In another embodiment, a nicotinamide mononucleotide based derivative compound that increases the level of intracellular NAD+ may be used for the treatment of wounds and/or burns to promote healing, including, for example, first-, second- or third-degree burns and/or thermal, chemical or electrical burns. The formulations may be administered topically, to the skin or mucosal tissue, as an ointment, lotion, cream, microemulsion, gel, solution or the like, as further described herein, within the context of a dosing regimen effective to bring about the desired result.

Topical formulations comprising one or more a nicotinamide mononucleotide based derivative compound that increases the level of intracellular NAD+ may also be used as preventive, e.g., chemopreventive, compositions. When used in a chemopreventive method, susceptible skin is treated prior to any visible condition in a particular individual.

In another embodiment, a nicotinamide mononucleotide based derivative compound that increases the level of intracellular NAD+ may be used for recovering from, treating, or preventing a disease or condition induced or exacerbated by cellular senescence in a subject; methods for decreasing the rate of senescence of a subject, e.g., after onset of senescence; methods for extending the lifespan of a subject; methods for recovering from, treating or preventing a disease or condition relating to lifespan; methods for recovering from, treating or preventing a disease or condition relating to the proliferative capacity of cells; and methods for recovering from, treating or preventing a disease or condition resulting from cell damage or death. In certain embodiments, the method does not act by decreasing the rate of occurrence of diseases that shorten the lifespan of a subject. In certain embodiments, a method does not act by reducing the lethality caused by a disease, such as cancer.

In yet another embodiment, a nicotinamide mononucleotide based derivative compound that increases the level of intracellular NAD+ may be administered to a subject in order to generally increase the lifespan of its cells and to protect its cells against stress and/or against apoptosis. It is believed that treating a subject with a compound described herein is similar to subjecting the subject to hormesis, i.e., mild stress that is beneficial to organisms and may extend their lifespan.

A nicotinamide mononucleotide based derivative compound that increases the level of intracellular NAD+ can also be administered to subjects for treatment of diseases, e.g., chronic diseases, associated with cell death, in order to protect the cells from cell death. Exemplary diseases include those associated with neural cell death, neuronal dysfunction, or muscular cell death or dysfunction, such as Parkinson's disease, Alzheimer's disease, multiple sclerosis, amyotropic lateral sclerosis, and muscular dystrophy; AIDS; fulminant hepatitis; diseases linked to degeneration of the brain, such as Creutzfeld-Jakob disease, retinitis pigmentosa and cerebellar degeneration; myelodysplasis such as aplastic anemia; ischemic diseases such as myocardial infarction and stroke; hepatic diseases such as alcoholic hepatitis, hepatitis B and hepatitis C; joint-diseases such as osteoarthritis; atherosclerosis; alopecia; damage to the skin due to UV light; lichen planus; atrophy of the skin; cataract; and graft rejections. Cell death can also be caused by surgery, drug therapy, chemical exposure or radiation exposure.

A nicotinamide mononucleotide based derivative compound that increases the level of intracellular NAD+ can also be administered to a subject suffering from an acute disease, e.g., damage to an organ or tissue, e.g., a subject suffering from stroke or myocardial infarction or a subject suffering from a spinal cord injury. A nicotinamide mononucleotide based derivative compound that increases the level of intracellular NAD+ may also be used to repair an alcoholic's liver.

In one embodiment, modulating NHD through NAD⁺ may directly regulate protein-protein interactions, the modulation of which may be useful in methods of recovering from, treating and preventing cancer, aging, cell death, radiation damage, radiation exposure, among others, may improve DNA repair, cell proliferation, cell survival, among others, and may increase the life span of a cell or protect it against certain stresses, among others. For example, cells in culture can be treated as described herein, such as to keep them proliferating longer. This is particularly useful for primary cell cultures (i.e., cells obtained from an organism, e.g., a human), which are known to have only a limited life span in culture. Treating such cells according to methods of the invention, e.g., by integrating one or more additional copies of one or more genes selected from the group consisting of NPT1, PNC1, NMA1, NMA2, nicotinamide N-methyl transferase (NNMT and NNT1), nicotinamide phosphoribosyltransferase (NAMPRT), and optionally human nicotinamide mononucleotide adenylyltransferase (NMNAT, NMAT-1, -2, and/or -3), will result in increasing the amount of time that the cells are kept alive in culture. Embryonic stem (ES) cells and pluripotent cells, and cells differentiated therefrom, can also be modified according to the methods of the invention such as to keep the cells or progeny thereof in culture for longer periods of time. Primary cultures of cells, ES cells, pluripotent cells and progeny thereof can be used, e.g., to identify compounds having particular biological effects on the cells or for testing the toxicity of compounds on the cells (i.e., cytotoxicity assays).

In other embodiments, cells that are intended to be preserved for long periods of time are treated as described herein. The cells can be cells in suspension, e.g., blood cells, or tissues or organs. For example, blood collected from an individual for administering to an individual can be treated according to the invention, such as to preserve the blood cells for longer periods of time. Other cells that one may treat for extending their lifespan and/or protect them against certain types of stresses include cells for consumption, e.g., cells from non-human mammals (such as meat), or plant cells (such as vegetables).

In another embodiment, cells obtained from a subject, e.g., a human or other mammal, are treated according to the methods of the invention and then administered to the same or a different subject. Accordingly, cells or tissues obtained from a donor for use as a graft can be treated as described herein prior to administering to the recipient of the graft. For example, bone marrow cells can be obtained from a subject, treated ex vivo to extend their life span and protect the cells against certain types of stresses and then administered to a recipient. In certain embodiments, the cells of the graft, e.g., bone marrow, are transfected with one or more copies of one or more genes selected from the group consisting of NPT1, PNC1, NMA1, NMA2, NMNAT-1, -2, and/or -3, NNT1, NAMPRT, and optionally NMAT-1 or 2. The graft can be an organ, a tissue or loose cells.

In yet other embodiments, cells are treated in vivo to increase their life span and/or protect them against certain types of stresses. For example, skin can be protected from aging, e.g., developing wrinkles, by treating skin, e.g., epithelial cells, as described herein. In an exemplary embodiment, skin is contacted with a pharmaceutical or cosmetic composition comprising a compound that is capable of increasing the transcription of one or more genes selected from the group consisting of NPT1, PNC1, NMA1, NMA2, NMNAT-1, -2, and/or -3, NNT1, NAMPRT, and optionally NMAT-1 or 2. In another embodiment, skin cells are contacted with a composition comprising a protein selected from the group consisting of NPT1, PNC1, NMA1, NMA2, NMNAT-1, -2, and/or -3, NNT1, NAMPRT, and optionally NMAT-1 or 2, or a nucleic acid encoding such, and a vehicle for delivering the nucleic acid or protein to the cells.

Compounds, nucleic acids and proteins can also be delivered to a tissue or organ within a subject, such as by injection, to extend the life span of the cells or protect the cells against certain stresses.

In yet another embodiment, an agent of the invention is administered to subjects, such as to generally increase the life span of its cells and protect its cells against certain types of stresses. For example, an agent can be taken by subjects as food supplements. In one embodiment, such an agent is a component of a multi-vitamin complex.

Agents that extend the life span of cells and protect them from stress can also be administered to subjects for treatement of diseases, e.g., chronic diseases, associated with cell death, such as to protect the cells from cell death, e.g., diseases associated with neural cell death or muscular cell death. Exemplary diseases include Parkinson's disease, Alzheimer's disease, multiple sclerosis, amniotropic lateral sclerosis, and muscular dystrophy. In such cases, the agent may be administered in the tissue or organ likely to encounter cell death.

Such agents can also be administered to a subject suffering from an acute damage to an organ or tissue, e.g., a subject suffering from stroke or myocardial infarction or a subject suffering from a spinal cord injury. Agents can also be used to repair an alcoholic's liver.

Since DNA repair is also inhibited by nicotinamide, agents that reduce nicotinamide levels in cells can be used to promote DNA repair in cells. Accordingly, cells exposed to conditions that may trigger DNA damage, e.g., U.S. radiation and ethidium bromide, may be protected by contacting them before, during and/or after exposure to the DNA damaging agent, with an agent that reduces nicotinamide levels in the cell.

In other embodiments, the methods of the invention are applied to yeast cells. Situations in which it may be desirable to extend the life span of yeast cells and to protect them against certain types of stress include any process in which yeast is used, e.g., the making of beer, yogurt, and bakery, e.g., making of bread. Use of yeast having an extended life span can result in using less yeast or in having the yeast be active for longer periods of time.

The invention also provides methods for reducing the life span of a cell or rendering it more susceptible to certain stresses, e.g., heatshock, radioactivity, osmotic stress, DNA damage, e.g., from U.V. Such methods can be used whenever it is desired to reduce the life span of a cell. Exemplary methods include decreasing the level or activity of a protein selected from the group consisting of NPT1, PNC1, NMA1, NMA2, NMNAT-1, -2, and/or -3, NNT1, NAMPRT, and optionally NMAT-1 or 2.

Another method includes increasing the level of nicotinamide in the cell, e.g., by contacting the cell with nicotinamide, or by increasing the level or activity of an enzyme stimulating nicotinamide biosynthesis or decreasing the level or activity of an enzyme inhibiting or degrading nicotinamide, e.g., by decreasing the level or activity of NPT1, PNC1, NMA1, NMA2, NMNAT-1, -2, and/or -3, NNT1, NAMPRT, and optionally NMAT-1 or 2. Exemplary situations in which one may wish to reduce the life span of a cell or render it more susceptible to certain stresses include treatment of cancer, autoimmune diseases or any other situation in which it is desirable to eliminate cells in a subject. Nicotinamide or other compounds or agents of the invention can be administered directly to the area containing the underirable cells, e.g., in a tumor. These methods can also be used to eliminate cells or prevent further proliferation of undesirable cells of non-malignant tumors, e.g., warts, beauty spots and fibromas. For example, nicotinamide can be injected into a wart, or alternatively be included in a pharmaceutical composition for applying onto the wart.

Methods for decreasing the life span of cells or increasing their susceptibility to certain stresses can be applied to yeast, e.g., yeast infecting subjects. Accordingly, a composition comprising an agent, e.g., nicotinamide, can be applied to the location of the yeast infection.

Subjects that may be treated as described herein include eukaryotes, such as mammals, e.g., humans, ovines, bovines, equines, porcines, canines, felines, non-human primate, mice, and rats. Cells that may be treated include eukaryotic cells, e.g., from a subject described above, or plant cells, yeast cells and prokaryotic cells, e.g., bacterial cells.

The compound or composition disclosed herein can be used for recovering from, treating, mitigating, or ameliorating various conditions pertaining to DNA repair deficiency disorder. For example, the compound or composition disclosed herein can be used for mitigation, treatment, or amelioration of a DNA repair deficiency disorder.

The invention method of use generally comprises administering to a subject (e.g., a human being) a compound or a composition disclosed herein. Such administering can be local administration or systemic administration, which administering can be achieved by, for example, oral administration, subcutaneous injection, intravenous injection, topical administration, or implant.

Examples of conditions related to DNA repair deficiency disorders include, but are not limited to, Ataxia Telangiectasia (A-T), Xeroderma Pigmentosum (XP), Fanconi's Anemia (FA), Li Fraumeni syndrome, Nijmegen breakage syndrome (NBS), A-T-like disorder (ATLD), Werner's syndrome, Bloom's syndrome, Rothmund-Thompson syndrome, Cockayne's syndrome (CS), Trichothiodystrophy, ATR-Seckel syndrome, LIG4 syndrome, Human immunodeficiency with microcephaly, Spinocerebellar ataxia with axonal neuropathy, Ataxia with oculomotor apraxia 1, Ataxia with oculomotor apraxia 2, Diamond-Blackfan anemia, Rapadilino syndrome, Turcot Syndrome, Seckle Syndrome, Lynch syndrome, NBS-like syndrome, and RIDDLE Syndrome and others like those.

In some embodiments, the methods include administering to the subject an effective amount of an agent that inhibits NHD complex formation.

In some embodiments, the methods further comprise administering to the subject an effective amount of an agent that increases the levels of NAD+ in the subject. Examples of such agents include NAD+ precursor, such as nicotinic acid, nicotinamide, nicotinamide mononucleotide (NMN), nicotinamide riboside (NR), or a salt thereof or prodrug thereof, including crystalline and polymorphic forms. In some embodiments, such an agent is administered at a dose of between 0.5-5 grams per day. In some embodiments, NMN is orally administered in doses of between 250 mg-5 grams per day. NAD+ levels also can be increased by increasing the activity of enzymes (or enzymatically active fragments thereof) involved in NAD+ biosynthesis (de novo synthesis or salvage pathways). Enzymes involved in NAD+ biosynthesis such as nicotinate phosphoribosyl transferase 1 (NPT1), pyrazinamidase/nicotinamidase 1 (PNC1), nicotinic acid mononucleotide adenylyltransf erase 1 (NMA1), nicotinic acid mononucleotide adenylyltransferase 2 (NMA2), nicotinamide N-methyltransferase (NNMT), nicotinamide phosphoribosyl transferase (NAMPT or NAMPRT), nicotinate/nicotinamide mononucleotide adenylyl transferase 1 (NMNAT-1), and nicotinamide mononucleotide adenylyl transferase 2 (NMNAT-2); are described in U.S. Pat. No. 7,977,049, which is incorporated by reference herein. The NHD inhibitor and agent that increases the levels of NAD+ can be administered simultaneously (e.g., as a single formulation) or sequentially (e.g., as separate formulations).

In some embodiments, the methods include administering to a subject an effective amount of an agent that increases the levels of NAD+, without administering an inhibitor of NHD.

Aspects of the invention thus relate to compositions of matter including NAD+ precursors, such as NMN or a salt thereof or prodrug thereof, including crystalline and polymorphic forms. Further aspects of the invention relate to compositions of matter including an enzyme involved in NAD+ biosynthesis, such as NMNAT-1, -2, and/or -3, or NAMPT, or an enzymatically active fragment thereof, or a nucleic acid encoding an enzyme involved in NAD+ biosynthesis, or an enzymatically active fragment thereof. In some embodiments, compositions include conjugates of agents described herein, such as fish oil conjugates.

In one embodiment, the invention provides a method for recovering from, treating, or preventing a disease or condition induced or exacerbated by cellular senescence in a subject; methods for decreasing the rate of senescence of a subject, e.g., after onset of senescence; methods for extending the lifespan of a subject; methods for recovering from, treating, or preventing a disease or condition relating to lifespan; methods for recovering from, treating, or preventing a disease or condition relating to the proliferative capacity of cells; and methods for recovering from, treating, or preventing a disease or condition resulting from cell damage or death. In certain embodiments, the disease or condition does not result from oxidative stress. In certain embodiments, a method does not significantly increase the resistance of the subject to oxidative stress. In certain embodiments, the method does not act by decreasing the rate of occurrence of diseases that shorten the lifespan of a subject. In certain embodiments, a method does not act by reducing the lethality caused by a disease, such as cancer.

In yet another embodiment, any of the compositions described herein is administered to a subject, such as to generally increase the lifespan of its cells and to protect its cells against stress and/or against apoptosis. It is believed that treating a subject with a composition described herein is similar to subjecting the subject to hormesis, i.e., mild stress that is beneficial to organisms and may extend their lifespan. For example, a composition can be taken by subjects as a food or dietary supplement. In one embodiment, such a composition is a component of a multi-vitamin complex. Compositions can also be added to existing formulations that are taken on a daily basis, e.g., statins and aspirin. Compositions may also be used as food additives.

Compositions described herein could also be taken as one component of a multi-drug complex or as a supplement in addition to a multi-drug regimen. In one embodiment, this multi-drug complex or regimen would include drugs or compositions for the treatment or prevention of aging-related diseases, e.g., stroke, heart disease, arthritis, high blood pressure, Alzheimer's. In another embodiment, this multi-drug regimen would include chemotherapeutic drugs for the treatment of cancer. In a specific embodiment, a composition could be used to protect non-cancerous cells from the effects of chemotherapy or for recovering from, treating, or preventing chemotherapy-induced damage.

Chemotherapeutic agents that may be coadministered with compositions described herein as having anti-cancer activity include: aminoglutethimide, amsacrine, anastrozole, asparaginase, bcg, bicalutamide, bleomycin, buserelin, busulfan, camptothecin, capecitabine, carboplatin, carmustine, chlorambucil, cisplatin, cladribine, clodronate, colchicine, cyclophosphamide, cyproterone, cytarabine, dacarbazine, dactinomycin, daunorubicin, dienestrol, diethylstilbestrol, docetaxel, doxorubicin, epirubicin, estradiol, estramustine, etoposide, exemestane, filgrastim, fludarabine, fludrocortisone, fluorouracil, fluoxymesterone, flutamide, gemcitabine, genistein, goserelin, hydroxyurea, idarubicin, ifosfamide, imatinib, interferon, irinotecan, irinotecan, letrozole, leucovorin, leuprolide, levamisole, lomustine, mechlorethamine, medroxyprogesterone, megestrol, melphalan, mercaptopurine, mesna, methotrexate, mitomycin, mitotane, mitoxantrone, nilutamide, nocodazole, ocreotide, oxaliplatin, paclitaxel, pamidronate, pentostatin, plicamycin, porfimer, procarbazine, raltitrexed, rituximab, streptozocin, suramin, tamoxifen, temozolomide, teniposide, testosterone, thioguanine, thiotepa, titanocene dichloride, topotecan, trastuzumab, tretinoin, vinblastine, vincristine, vindesine, and vinorelbine.

These chemotherapeutic agents may be categorized by their mechanism of action into, for example, following groups: anti-metabolites/anti-cancer agents, such as pyrimidine analogs (5-fluorouracil, floxuridine, capecitabine, gemcitabine and cytarabine) and purine analogs, folate antagonists and related inhibitors (mercaptopurine, thioguanine, pentostatin and 2-chlorodeoxyadenosine (cladribine)); antiproliferative/antimitotic agents including natural products such as vinca alkaloids (vinblastine, vincristine, and vinorelbine), microtubule disrupters such as taxane (paclitaxel, docetaxel), vincristin, vinblastin, nocodazole, epothilones and navelbine, epidipodophyllotoxins (teniposide), DNA damaging agents (actinomycin, amsacrine, anthracyclines, bleomycin, busulfan, camptothecin, carboplatin, chlorambucil, cisplatin, cyclophosphamide, cytoxin, dactinomycin, daunorubicin, docetaxel, doxorubicin, epirubicin, hexamethylmelamineoxaliplatin, iphosphamide, melphalan, mechlorethamine, mitomycin, mitoxantrone, nitrosourea, paclitaxel, plicamycin, procarbazine, teniposide, triethiylenethiophosphoramide and etoposide (VP16)); antibiotics such as dactinomycin (actinomycin D), daunorubicin, doxorubicin (adriamycin), idarubicin, anthracyclines, mitoxantrone, bleomycins, plicamycin (mithramycin) and mitomycin; enzymes (L-asparaginase which systemically metabolizes L-asparagine and deprives cells which do not have the capacity to synthesize their own asparagine); antiplatelet agents; antiproliferative/antimitotic alkylating agents such as nitrogen mustards (mechlorethamine, cyclophosphamide and analogs, melphalan, chlorambucil), ethylenimines and methylmelamines (hexamethylmelamine and thiotepa), alkyl sulfonates-busulfan, nitrosoureas (carmustine (BCNU) and analogs, streptozocin), trazenes-dacarbazinine (DTIC); antiproliferative/antimitotic antimetabolites such as folic acid analogs (methotrexate); platinum coordination complexes (cisplatin, carboplatin), procarbazine, hydroxyurea, mitotane, aminoglutethimide; hormones, hormone analogs (estrogen, tamoxifen, goserelin, bicalutamide, nilutamide) and aromatase inhibitors (letrozole, anastrozole); anticoagulants (heparin, synthetic heparin salts and other inhibitors of thrombin); fibrinolytic agents (such as tissue plasminogen activator, streptokinase and urokinase), aspirin, COX-2 inhibitors, dipyridamole, ticlopidine, clopidogrel, abciximab; antimigratory agents; antisecretory agents (breveldin); immunosuppressives (cyclosporine, tacrolimus (FK-506), sirolimus (rapamycin), azathioprine, mycophenolate mofetil); anti-angiogenic compositions (TNP-470, genistein) and growth factor inhibitors (vascular endothelial growth factor (VEGF) inhibitors, fibroblast growth factor (FGF) inhibitors, epidermal growth factor (EGF) inhibitors); angiotensin receptor blocker; nitric oxide donors; anti-sense oligonucleotides; antibodies (trastuzumab); cell cycle inhibitors and differentiation inducers (tretinoin); mTOR inhibitors, topoisomerase inhibitors (doxorubicin (adriamycin), amsacrine, camptothecin, daunorubicin, dactinomycin, eniposide, epirubicin, etoposide, idarubicin, irinotecan (CPT-11) and mitoxantrone, topotecan, irinotecan), corticosteroids (cortisone, dexamethasone, hydrocortisone, methylprednisolone, prednisone, and prednisolone); growth factor signal transduction kinase inhibitors; mitochondrial dysfunction inducers and caspase activators; chromatin disrupters.

These chemotherapeutic agents may be used by themselves with a composition described herein as inducing cell death or reducing lifespan or increasing sensitivity to stress and/or in combination with other chemotherapeutics agents. Many combinatorial therapies have been developed, including but not limited to, those listed in Table 5.

TABLE 5 Exemplary conventional combination cancer chemotherapy Name Therapeutic agents ABV Doxorubicin, Bleomycin, Vinblastine ABVD Doxorubicin, Bleomycin, Vinblastine, Dacarbazine AC (Breast) Doxorubicin, Cyclophosphamide AC (Sarcoma) Doxorubicin, Cisplatin AC (Neuroblastoma) Cyclophosphamide, Doxorubicin ACE Cyclophosphamide, Doxorubicin, Etoposide ACe Cyclophosphamide, Doxorubicin AD Doxorubicin, Dacarbazine AP Doxorubicin, Cisplatin ARAC-DNR Cytarabine, Daunorubicin B-CAVe Bleomycin, Lomustine, Doxorubicin, Vinblastine BCVPP Carmustine, Cyclophosphamide, Vinblastine, Procarbazine, Prednisone BEACOPP Bleomycin, Etoposide, Doxorubicin, Cyclophosphamide, Vincristine, Procarbazine, Prednisone, Filgrastim BEP Bleomycin, Etoposide, Cisplatin BIP Bleomycin, Cisplatin, Ifosfamide, Mesna BOMP Bleomycin, Vincristine, Cisplatin, Mitomycin CA Cytarabine, Asparaginase CABO Cisplatin, Methotrexate, Bleomycin, Vincristine CAF Cyclophosphamide, Doxorubicin, Fluorouracil CAL-G Cyclophosphamide, Daunorubicin, Vincristine, Prednisone, Asparaginase CAMP Cyclophosphamide, Doxorubicin, Methotrexate, Procarbazine CAP Cyclophosphamide, Doxorubicin, Cisplatin CaT Carboplatin, Paclitaxel CAV Cyclophosphamide, Doxorubicin, Vincristine CAVE ADD CAV and Etoposide CA-VP16 Cyclophosphamide, Doxorubicin, Etoposide CC Cyclophosphamide, Carboplatin CDDP/VP-16 Cisplatin, Etoposide CEF Cyclophosphamide, Epirubicin, Fluorouracil CEPP(B) Cyclophosphamide, Etoposide, Prednisone, with or without/ Bleomycin CEV Cyclophosphamide, Etoposide, Vincristine CF Cisplatin, Fluorouracil or Carboplatin Fluorouracil CHAP Cyclophosphamide or Cyclophosphamide, Altretamine, Doxorubicin, Cisplatin ChlVPP Chlorambucil, Vinblastine, Procarbazine, Prednisone CHOP Cyclophosphamide, Doxorubicin, Vincristine, Prednisone CHOP-BLEO Add Bleomycin to CHOP CISCA Cyclophosphamide, Doxorubicin, Cisplatin CLD-BOMP Bleomycin, Cisplatin, Vincristine, Mitomycin CMF Methotrexate, Fluorouracil, Cyclophosphamide CMFP Cyclophosphamide, Methotrexate, Fluorouracil, Prednisone CMFVP Cyclophosphamide, Methotrexate, Fluorouracil, Vincristine, Prednisone CMV Cisplatin, Methotrexate, Vinblastine CNF Cyclophosphamide, Mitoxantrone, Fluorouracil CNOP Cyclophosphamide, Mitoxantrone, Vincristine, Prednisone COB Cisplatin, Vincristine, Bleomycin CODE Cisplatin, Vincristine, Doxorubicin, Etoposide COMLA Cyclophosphamide, Vincristine, Methotrexate, Leucovorin, Cytarabine COMP Cyclophosphamide, Vincristine, Methotrexate, Prednisone Cooper Regimen Cyclophosphamide, Methotrexate, Fluorouracil, Vincristine, Prednisone COP Cyclophosphamide, Vincristine, Prednisone COPE Cyclophosphamide, Vincristine, Cisplatin, Etoposide COPP Cyclophosphamide, Vincristine, Procarbazine, Prednisone CP(Chronic lymphocytic Chlorambucil, Prednisone leukemia) CP (Ovarian Cancer) Cyclophosphamide, Cisplatin CT Cisplatin, Paclitaxel CVD Cisplatin, Vinblastine, Dacarbazine CVI Carboplatin, Etoposide, Ifosfamide, Mesna CVP Cyclophosphamide, Vincristine, Prednisome CVPP Lomustine, Procarbazine, Prednisone CYVADIC Cyclophosphamide, Vincristine, Doxorubicin, Dacarbazine DA Daunorubicin, Cytarabine DAT Daunorubicin, Cytarabine, Thioguanine DAV Daunorubicin, Cytarabine, Etoposide DCT Daunorubicin, Cytarabine, Thioguanine DHAP Cisplatin, Cytarabine, Dexamethasone DI Doxorubicin, Ifosfamide DTIC/Tamoxifen Dacarbazine, Tamoxifen DVP Daunorubicin, Vincristine, Prednisone EAP Etoposide, Doxorubicin, Cisplatin EC Etoposide, Carboplatin EFP Etoposie, Fluorouracil, Cisplatin ELF Etoposide, Leucovorin, Fluorouracil EMA 86 Mitoxantrone, Etoposide, Cytarabine EP Etoposide, Cisplatin EVA Etoposide, Vinblastine FAC Fluorouracil, Doxorubicin, Cyclophosphamide FAM Fluorouracil, Doxorubicin, Mitomycin FAMTX Methotrexate, Leucovorin, Doxorubicin FAP Fluorouracil, Doxorubicin, Cisplatin F-CL Fluorouracil, Leucovorin FEC Fluorouracil, Cyclophosphamide, Epirubicin FED Fluorouracil, Etoposide, Cisplatin FL Flutamide, Leuprolide FZ Flutamide, Goserelin acetate implant HDMTX Methotrexate, Leucovorin Hexa-CAF Altretamine, Cyclophosphamide, Methotrexate, Fluorouracil ICE-T Ifosfamide, Carboplatin, Etoposide, Paclitaxel, Mesna IDMTX/6-MP Methotrexate, Mercaptopurine, Leucovorin IE Ifosfamide, Etoposie, Mesna IfoVP Ifosfamide, Etoposide, Mesna IPA Ifosfamide, Cisplatin, Doxorubicin M-2 Vincristine, Carmustine, Cyclophosphamide, Prednisone, Melphalan MAC-III Methotrexate, Leucovorin, Dactinomycin, Cyclophosphamide MACC Methotrexate, Doxorubicin, Cyclophosphamide, Lomustine MACOP-B Methotrexate, Leucovorin, Doxorubicin, Cyclophosphamide, Vincristine, Bleomycin, Prednisone MAID Mesna, Doxorubicin, Ifosfamide, Dacarbazine m-BACOD Bleomycin, Doxorubicin, Cyclophosphamide, Vincristine, Dexamethasone, Methotrexate, Leucovorin MBC Methotrexate, Bleomycin, Cisplatin MC Mitoxantrone, Cytarabine MF Methotrexate, Fluorouracil, Leucovorin MICE Ifosfamide, Carboplatin, Etoposide, Mesna MINE Mesna, Ifosfamide, Mitoxantrone, Etoposide mini-BEAM Carmustine, Etoposide, Cytarabine, Melphalan MOBP Bleomycin, Vincristine, Cisplatin, Mitomycin MOP Mechlorethamine, Vincristine, Procarbazine MOPP Mechlorethamine, Vincristine, Procarbazine, Prednisone MOPP/ABV Mechlorethamine, Vincristine, Procarbazine, Prednisone, Doxorubicin, Bleomycin, Vinblastine MP (multiple myeloma) Melphalan, Prednisone MP (prostate cancer) Mitoxantrone, Prednisone MTX/6-MO Methotrexate, Mercaptopurine MTX/6-MP/VP Methotrexate, Mercaptopurine, Vincristine, Prednisone MTX-CDDPAdr Methotrexate, Leucovorin, Cisplatin, Doxorubicin MV (breast cancer) Mitomycin, Vinblastine MV (acute myelocytic leukemia) Mitoxantrone, Etoposide M-VAC Methotrexate Vinblastine, Doxorubicin, Cisplatin MVP Mitomycin Vinblastine, Cisplatin MVPP Mechlorethamine, Vinblastine, Procarbazine, Prednisone NFL Mitoxantrone, Fluorouracil, Leucovorin NOVP Mitoxantrone, Vinblastine, Vincristine OPA Vincristine, Prednisone, Doxorubicin OPPA Add Procarbazine to OPA. PAC Cisplatin, Doxorubicin PAC-I Cisplatin, Doxorubicin, Cyclophosphamide PA-CI Cisplatin, Doxorubicin PC Paclitaxel, Carboplatin or Paclitaxel, Cisplatin PCV Lomustine, Procarbazine, Vincristine PE Paclitaxel, Estramustine PFL Cisplatin, Fluorouracil, Leucovorin POC Prednisone, Vincristine, Lomustine ProMACE Prednisone, Methotrexate, Leucovorin, Doxorubicin, Cyclophosphamide, Etoposide ProMACE/cytaBOM Prednisone, Doxorubicin, Cyclophosphamide, Etoposide, Cytarabine, Bleomycin, Vincristine, Methotrexate, Leucovorin, Cotrimoxazole PRoMACE/MOPP Prednisone, Doxorubicin, Cyclophosphamide, Etoposide, Mechlorethamine, Vincristine, Procarbazine, Methotrexate, Leucovorin Pt/VM Cisplatin, Teniposide PVA Prednisone, Vincristine, Asparaginase PVB Cisplatin, Vinblastine, Bleomycin PVDA Prednisone, Vincristine, Daunorubicin, Asparaginase SMF Streptozocin, Mitomycin, Fluorouracil TAD Mechlorethamine, Doxorubicin, Vinblastine, Vincristine, Bleomycin, Etoposide, Prednisone TCF Paclitaxel, Cisplatin, Fluorouracil TIP Paclitaxel, Ifosfamide, Mesna, Cisplatin TTT Methotrexate, Cytarabine, Hydrocortisone Topo/CTX Cyclophosphamide, Topotecan, Mesna VAB-6 Cyclophosphamide, Dactinomycin, Vinblastine, Cisplatin, Bleomycin VAC Vincristine, Dactinomycin, Cyclophosphamide VACAdr Vincristine, Cyclophosphamide, Doxorubicin, Dactinomycin, Vincristine VAD Vincristine, Doxorubicin, Dexamethasone VATH Vinblastine, Doxorubicin, Thiotepa, Flouxymesterone VBAP Vincristine, Carmustine, Doxorubicin, Prednisone VBCMP Vincristine, Carmustine, Melphalan, Cyclophosphamide, Prednisone VC Vinorelbine, Cisplatin VCAP Vincristine, Cyclophosphamide, Doxorubicin, Prednisone VD Vinorelbine, Doxorubicin VelP Vinblastine, Cisplatin, Ifosfamide, Mesna VIP Etoposide, Cisplatin, Ifosfamide, Mesna VM Mitomycin, Vinblastine VMCP Vincristine, Melphalan, Cyclophosphamide, Prednisone VP Etoposide, Cisplatin V-TAD Etoposide, Thioguanine, Daunorubicin, Cytarabine 5 + 2 Cytarabine, Daunorubicin, Mitoxantrone 7 + 3 Cytarabine with/, Daunorubicin or Idarubicin or Mitoxantrone “8 in 1” Methylprednisolone, Vincristine, Lomustine, Procarbazine, Hydroxyurea, Cisplatin, Cytarabine, Dacarbazine

In addition to conventional chemotherapeutics, the compositions described herein as capable of inducing cell death or reducing lifespan can also be used with antisense RNA, RNAi or other polynucleotides to inhibit the expression of the cellular components that contribute to unwanted cellular proliferation that are targets of conventional chemotherapy. Such targets are, merely to illustrate, growth factors, growth factor receptors, cell cycle regulatory proteins, transcription factors, or signal transduction kinases.

The methods may be advantageous over combination therapies known in the art because they may allow conventional chemotherapeutic agents to exert greater effect at lower dosage. In a preferred embodiment, the effective dose (ED₅₀) for a chemotherapeutic agent or combination of conventional chemotherapeutic agents when used in combination with a composition described herein is at least 2 fold less than the ED50 for the chemotherapeutic agent alone, and even more preferably at 5 fold, 10 fold or even 25 fold less. Conversely, the therapeutic index (TI) for such chemotherapeutic agent or combination of such chemotherapeutic agent when used in combination with a composition described herein can be at least 2 fold greater than the TI for conventional chemotherapeutic regimen alone, and even more preferably at 5 fold, 10 fold or even 25 fold greater.

Other combination therapies include conjoint administration with nicotinamide, NAD+ or salts thereof, or other Vitamin B3 analogs. Carnitines, such as L-carnitine, may also be co-administered, particularly for recovering from, treating, or preventing cerebral stroke, loss of memory, pre-senile dementia, Alzheimer's disease or preventing or treating disorders elicited by the use of neurotoxic drugs. Cyclooxygenase inhibitors, e.g., a COX-2 inhibitor, may also be co-administered for recovering from, treating, or preventing certain conditions described herein, such as an inflammatory condition or a neurologic disease.

Pharmaceutical Compositions

Compounds, nucleic acids, proteins, antibodies cells and other compositions can be administered to a subject according to methods known in the art. For example, nucleic acids encoding a protein or an antisense molecule can be administered to a subject as described above, e.g., using a viral vector. Cells can be administered according to methods for administering a graft to a subject, which may be accompanied, e.g., by administration of an immunosuppressant drug, e.g., cyclosporin A. For general principles in medicinal formulation, the reader is referred to Cell Therapy: Stem Cell Transplantation, Gene Therapy, and Cellular Immunotherapy, by G. Morstyn & W. Sheridan eds, Cambridge University Press, 1996; and Hematopoietic Stem Cell Therapy, E. D. Ball, J. Lister & P. Law, Churchill Livingstone, 2000.

The compounds of this invention are formulated with conventional carriers and excipients, which will be selected in accord with ordinary practice. Tablets will contain excipients, glidants, fillers, binders and the like. Aqueous formulations are prepared in sterile form, and when intended for delivery by other than oral administration generally will be isotonic. All formulations will optionally contain excipients such as those set forth in the “Handbook of Pharmaceutical Excipients” (1986). Excipients include ascorbic acid and other antioxidants, chelating agents such as EDTA, carbohydrates such as dextran, hydroxyalkylcellulose, hydroxyalkylmethylcellulose, stearic acid and the like. The pH of the formulations ranges from about 3 to about 11, but is ordinarily about 7 to 10. While it is possible for the active ingredients to be administered alone it may be preferable to present them as pharmaceutical formulations. The formulations, both for veterinary and for human use, of the invention comprise at least one active ingredient, as above defined, together with one or more acceptable carriers therefor and optionally other therapeutic ingredients. The carrier(s) must be “acceptable” in the sense of being compatible with the other ingredients of the formulation and physiologically innocuous to the recipient thereof. The formulations include those suitable for the foregoing administration routes. The formulations may conveniently be presented in unit dosage form and may be prepared by any of the methods well known in the art of pharmacy. Techniques and formulations generally are found in Remington's Pharmaceutical Sciences (Mack Publishing Co., Easton, Pa.). Such methods include the step of bringing into association the active ingredient with the carrier which constitutes one or more accessory ingredients. In general the formulations are prepared by uniformly and intimately bringing into association the active ingredient with liquid carriers or finely divided solid carriers or both, and then, if necessary, shaping the product.

Formulations of the present invention suitable for oral administration may be presented as discrete units such as capsules, cachets or tablets each containing a predetermined amount of the active ingredient; as a powder or granules; as a solution or a suspension in an aqueous or non-aqueous liquid; or as an oil-in-water liquid emulsion or a water-in-oil liquid emulsion. The active ingredient may also be administered as a bolus, electuary or paste.

A tablet is made by compression or molding, optionally with one or more accessory ingredients. Compressed tablets may be prepared by compressing in a suitable machine the active ingredient in a free-flowing form such as a powder or granules, optionally mixed with a binder, lubricant, inert diluent, preservative, surface active or dispersing agent. Molded tablets may be made by molding in a suitable machine a mixture of the powdered active ingredient moistened with an inert liquid diluent. The tablets may optionally be coated or scored and optionally are formulated so as to provide slow or controlled release of the active ingredient therefrom.

For infections of the eye or other external tissues e.g. mouth (such as oral mucositis, gum disease, periodontal disease, tooth decay) and skin, the formulations are preferably applied as a topical ointment or cream containing the active ingredient(s) in an amount of, for example, 0.075 to 20% w/w (including active ingredient(s) in a range between 0.1% and 20% in increments of 0.1% w/w such as 0.6% w/w, 0.7% w/w, etc.), preferably 0.2 to 15% w/w and most preferably 0.5 to 10% w/w. When formulated in an ointment, the active ingredients may be employed with either a paraffinic or a water-miscible ointment base. Alternatively, the active ingredients may be formulated in a cream with an oil-in-water cream base.

If desired, the aqueous phase of the cream base may include, for example, at least 30% w/w of a polyhydric alcohol, i.e. an alcohol having two or more hydroxyl groups such as propylene glycol, butane 1,3-diol, mannitol, sorbitol, glycerol and polyethylene glycol (including PEG 400) and mixtures thereof. The topical formulations may desirably include a compound which enhances absorption or penetration of the active ingredient through the skin or other affected areas. Examples of such dermal penetration enhancers include dimethyl sulphoxide and related analogs.

The oily phase of the emulsions of this invention may be constituted from known ingredients in a known manner. While the phase may comprise merely an emulsifier (otherwise known as an emulgent), it desirably comprises a mixture of at least one emulsifier with a fat or an oil or with both a fat and an oil. Preferably, a hydrophilic emulsifier is included together with a lipophilic emulsifier which acts as a stabilizer. It is also preferred to include both an oil and a fat. Together, the emulsifier(s) with or without stabilizer(s) make up the so-called emulsifying wax, and the wax together with the oil and fat make up the so-called emulsifying ointment base which forms the oily dispersed phase of the cream formulations.

Emulgents and emulsion stabilizers suitable for use in the formulation of the invention include Tween™ 60, Span™ 80, cetostearyl alcohol, benzyl alcohol, myristyl alcohol, glyceryl mono-stearate and sodium lauryl sulfate.

The choice of suitable oils or fats for the formulation is based on achieving the desired cosmetic properties. The cream should preferably be a non-greasy, non-staining and washable product with suitable consistency to avoid leakage from tubes or other containers. Straight or branched chain, mono- or dibasic alkyl esters such as di-isoadipate, isocetyl stearate, propylene glycol diester of coconut fatty acids, isopropyl myristate, decyl oleate, isopropyl palmitate, butyl stearate, 2-ethylhexyl palmitate or a blend of branched chain esters known as Crodamol CAP may be used, the last three being preferred esters. These may be used alone or in combination depending on the properties required. Alternatively, high melting point lipids such as white soft paraffin and/or liquid paraffin or other mineral oils are used.

Pharmaceutical formulations according to the present invention comprise a combination according to the invention together with one or more pharmaceutically acceptable carriers or excipients and optionally other therapeutic agents. Pharmaceutical formulations containing the active ingredient may be in any form suitable for the intended method of administration. When used for oral use for example, tablets, troches, lozenges, aqueous or oil suspensions, dispersible powders or granules, emulsions, hard or soft capsules, syrups or elixirs may be prepared. Compositions intended for oral use may be prepared according to any method known to the art for the manufacture of pharmaceutical compositions and such compositions may contain one or more agents including sweetening agents, flavoring agents, coloring agents and preserving agents, in order to provide a palatable preparation. Tablets containing the active ingredient in admixture with non-toxic pharmaceutically acceptable excipient which are suitable for manufacture of tablets are acceptable. These excipients may be, for example, inert diluents, such as calcium or sodium carbonate, lactose, calcium or sodium phosphate; granulating and disintegrating agents, such as maize starch, or alginic acid; binding agents, such as starch, gelatin or acacia; and lubricating agents, such as magnesium stearate, stearic acid or talc. Tablets may be uncoated or may be coated by known techniques including microencapsulation to delay disintegration and adsorption in the gastrointestinal tract and thereby provide a sustained action over a longer period. For example, a time delay material such as glyceryl monostearate or glyceryl distearate alone or with a wax may be employed.

Formulations for oral use may be also presented as hard gelatin capsules where the active ingredient is mixed with an inert solid diluent, for example calcium phosphate or kaolin, or as soft gelatin capsules wherein the active ingredient is mixed with water or an oil medium, such as peanut oil, liquid paraffin or olive oil.

Aqueous suspensions of the invention contain the active materials in admixture with excipients suitable for the manufacture of aqueous suspensions. Such excipients include a suspending agent, such as sodium carboxymethylcellulose, methylcellulose, hydroxypropyl methylcelluose, sodium alginate, polyvinylpyrrolidone, gum tragacanth and gum acacia, and dispersing or wetting agents such as a naturally-occurring phosphatide (e.g., lecithin), a condensation product of an alkylene oxide with a fatty acid (e.g., polyoxyethylene stearate), a condensation product of ethylene oxide with a long chain aliphatic alcohol (e.g., heptadecaethyleneoxycetanol), a condensation product of ethylene oxide with a partial ester derived from a fatty acid and a hexitol anhydride (e.g., polyoxyethylene sorbitan monooleate). The aqueous suspension may also contain one or more preservatives such as ethyl or n-propyl p-hydroxy-benzoate, one or more coloring agents, one or more flavoring agents and one or more sweetening agents, such as sucrose or saccharin.

Oil suspensions may be formulated by suspending the active ingredient in a vegetable oil, such as arachis oil, olive oil, sesame oil or coconut oil, or in a mineral oil such as liquid paraffin. The oral suspensions may contain a thickening agent, such as beeswax, hard paraffin or cetyl alcohol. Sweetening agents, such as those set forth above, and flavoring agents may be added to provide a palatable oral preparation. These compositions may be preserved by the addition of an antioxidant such as ascorbic acid. Dispersible powders and granules of the invention suitable for preparation of an aqueous suspension by the addition of water provide the active ingredient in admixture with a dispersing or wetting agent, a suspending agent, and one or more preservatives. Suitable dispersing or wetting agents and suspending agents are exemplified by those disclosed above. Additional excipients, for example sweetening, flavoring and coloring agents, may also be present.

The pharmaceutical compositions of the invention may also be in the form of oil-in-water emulsions. The oily phase may be a vegetable oil, such as olive oil or arachis oil, a mineral oil, such as liquid paraffin, or a mixture of these. Suitable emulsifying agents include naturally-occurring gums, such as gum acacia and gum tragacanth, naturally-occurring phosphatides, such as soybean lecithin, esters or partial esters derived from fatty acids and hexitol anhydrides, such as sorbitan monooleate, and condensation products of these partial esters with ethylene oxide, such as polyoxyethylene sorbitan monooleate. The emulsion may also contain sweetening and flavoring agents. Syrups and elixirs may be formulated with sweetening agents, such as glycerol, sorbitol or sucrose. Such formulations may also contain a demulcent, a preservative, a flavoring or a coloring agent.

The pharmaceutical compositions of the invention may be in the form of a sterile injectable preparation, such as a sterile injectable aqueous or oleaginous suspension. This suspension may be formulated according to the known art using those suitable dispersing or wetting agents and suspending agents which have been mentioned above. The sterile injectable preparation may also be a sterile injectable solution or suspension in a non-toxic parenterally acceptable diluent or solvent, such as a solution in 1,3-butane-diol or prepared as a lyophilized powder. Among the acceptable vehicles and solvents that may be employed are water, Ringer's solution and isotonic sodium chloride solution. In addition, sterile fixed oils may conventionally be employed as a solvent or suspending medium. For this purpose any bland fixed oil may be employed including synthetic mono- or diglycerides. In addition, fatty acids such as oleic acid may likewise be used in the preparation of injectables.

The amount of active ingredient that may be combined with the carrier material to produce a single dosage form will vary depending upon the host treated and the particular mode of administration. For example, a time-release formulation intended for oral administration to humans may contain approximately 1 to 1000 mg of active material compounded with an appropriate and convenient amount of carrier material which may vary from about 5 to about 95% of the total compositions (weight:weight). The pharmaceutical composition can be prepared to provide easily measurable amounts for administration. For example, an aqueous solution intended for intravenous infusion may contain from about 3 to 500.mu.g of the active ingredient per milliliter of solution in order that infusion of a suitable volume at a rate of about 30 mL/hr can occur.

Formulations suitable for topical administration to the eye also include eye drops wherein the active ingredient is dissolved or suspended in a suitable carrier, especially an aqueous solvent for the active ingredient. The active ingredient is preferably present in such formulations in a concentration of 0.5 to 20%, advantageously 0.5 to 10%, and particularly about 1.5% w/w.

Formulations suitable for topical administration in the mouth include lozenges comprising the active ingredient in a flavored basis, usually sucrose and acacia or tragacanth; pastilles comprising the active ingredient in an inert basis such as gelatin and glycerin, or sucrose and acacia; and mouthwashes comprising the active ingredient in a suitable liquid carrier.

Formulations for rectal administration may be presented as a suppository with a suitable base comprising for example cocoa butter or a salicylate. Formulations suitable for intrapulmonary or nasal administration have a particle size for example in the range of 0.1 to 500 microns, such as 0.5, 1, 30, 35 etc., which is administered by rapid inhalation through the nasal passage or by inhalation through the mouth so as to reach the alveolar sacs. Suitable formulations include aqueous or oily solutions of the active ingredient. Formulations suitable for aerosol or dry powder administration may be prepared according to conventional methods and may be delivered with other therapeutic agents such as compounds heretofore used in the treatment or prophylaxis of HCV infections as described below.

Formulations suitable for vaginal administration may be presented as pessaries, tampons, creams, gels, pastes, foams or spray formulations containing in addition to the active ingredient such carriers as are known in the art to be appropriate. Formulations suitable for parenteral administration include aqueous and non-aqueous sterile injection solutions which may contain anti-oxidants, buffers, bacteriostats and solutes which render the formulation isotonic with the blood of the intended recipient; and aqueous and non-aqueous sterile suspensions which may include suspending agents and thickening agents.

The formulations are presented in unit-dose or multi-dose containers, for example sealed ampoules and vials, and may be stored in a freeze-dried (lyophilized) condition requiring only the addition of the sterile liquid carrier, for example water for injection, immediately prior to use. Extemporaneous injection solutions and suspensions are prepared from sterile powders, granules and tablets of the kind previously described. Preferred unit dosage formulations are those containing a daily dose or unit daily sub-dose, as herein above recited, or an appropriate fraction thereof, of the active ingredient.

It should be understood that in addition to the ingredients particularly mentioned above the formulations of this invention may include other agents conventional in the art having regard to the type of formulation in question, for example those suitable for oral administration may include flavoring agents.

The invention further provides veterinary compositions comprising at least one active ingredient as above defined together with a veterinary carrier therefor.

Veterinary carriers are materials useful for the purpose of administering the composition and may be solid, liquid or gaseous materials which are otherwise inert or acceptable in the veterinary art and are compatible with the active ingredient. These veterinary compositions may be administered orally, parenterally or by any other desired route.

Compounds of the invention are used to provide controlled release pharmaceutical formulations containing as active ingredient one or more compounds of the invention (“controlled release formulations”) in which the release of the active ingredient are controlled and regulated to allow less frequency dosing or to improve the pharmacokinetic or toxicity profile of a given active ingredient.

Effective dose of active ingredient depends at least on the nature of the condition being treated, toxicity, whether the compound is being used prophylactically (lower doses) or against an active viral infection, the method of delivery, and the pharmaceutical formulation, and will be determined by the clinician using conventional dose escalation studies. It can be expected to be from about 0.0001 to about 100 mg/kg body weight per day; typically, from about 0.01 to about 10 mg/kg body weight per day; more typically, from about 0.01 to about 5 mg/kg body weight per day; most typically, from about 0.05 to about 0.5 mg/kg body weight per day. For example, the daily candidate dose for an adult human of approximately 70 kg body weight will range from 1 mg to 1000 mg, preferably between 5 mg and 500 mg, and may take the form of single or multiple doses.

One or more compounds of the invention (herein referred to as the active ingredients) are administered by any route appropriate to the condition to be treated. Suitable routes include oral, rectal, nasal, topical (including buccal and sublingual), vaginal and parenteral (including subcutaneous, intramuscular, intravenous, intradermal, intrathecal and epidural), and the like. It will be appreciated that the preferred route may vary with for example the condition of the recipient. An advantage of the compounds of this invention is that they are orally bioavailable and can be dosed orally.

The practice of the present invention will employ, unless otherwise indicated, conventional techniques of cell biology, cell culture, molecular biology, transgenic biology, microbiology, recombinant DNA, and immunology, which are within the skill of the art. Such techniques are explained fully in the literature. See, for example, Molecular Cloning A Laboratory Manual, 2^(nd) Ed., ed. by Sambrook, Fritsch and Maniatis (Cold Spring Harbor Laboratory Press: 1989); DNA Cloning, Volumes I and II (D. N. Glover ed., 1985); Oligonucleotide Synthesis (M. J. Gait ed., 1984); Mullis et al. U.S. Pat. No. 4,683,195; Nucleic Acid Hybridization (B. D. Hames & S. J. Higgins eds. 1984); Transcription And Translation (B. D. Hames & S. J. Higgins eds. 1984); Culture Of Animal Cells (R. I. Freshney, Alan R. Liss, Inc., 1987); Immobilized Cells And Enzymes (IRL Press, 1986); B. Perbal, A Practical Guide To Molecular Cloning (1984); the treatise, Methods In Enzymology (Academic Press, Inc., N.Y.); Gene Transfer Vectors For Mammalian Cells (J. H. Miller and M. P. Calos eds., 1987, Cold Spring Harbor Laboratory); Methods In Enzymology, Vols. 154 and 155 (Wu et al. eds.), Immunochemical Methods In Cell And Molecular Biology (Mayer and Walker, eds., Academic Press, London, 1987); Handbook Of Experimental Immunology, Volumes I-IV (D. M. Weir and C. C. Blackwell, eds., 1986); Manipulating the Mouse Embryo, (Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., 1986).

As can be appreciated from the disclosure above, the present invention has a wide variety of applications. The invention is further illustrated by the following examples, which are only illustrative and are not intended to limit the definition and scope of the invention in any way.

EXAMPLES Example 1: Materials and Methods 1. Chemical Reagents

All chemicals were purchased from Sigma Aldrich, with the following exceptions: PJ34 (Orchid Pharmaceuticals), 3-AB (Calbiochem) and EX-527 (Tocris Bioscience). NR and carba-NAD were synthesized and provided by Sirtris, a GSK company.

2. Constructs/Mutagenesis

The constructs used for stable expression of full-length and truncated human Flag-DBC1, have been previously described (24). The transient expression plasmids for human pcDNA 3.1 V5/His-DBC1 were constructed by cloning human DBC1 cDNA into pcDNA3.1 vector. Myc-DDK-tagged human PARP1 (Flag-PARP1) was purchased from OriGene (RC207085). Point mutants or deletion mutants for Flag-DBC1, V5/His-DBC1 or Flag-PARP1 were generated using Quickchange II XL Site Directed Mutagenesis kit (Stratagene), and verified by DNA sequencing (Dana-Farber/Harvard Cancer Center DNA Resource Core, Boston, Mass.). The constructs overexpressing mouse NMNAT1: pEGFP-N1 vector and pEGFP-N2-NMNAT1, were gifts from Dr. Shin-Ichiro Imai, Washington University School of Medicine (25). The constructs overexpressing the rat BRCT domain of PARP1 was a gift from Dr. Robert London, National Institute of Environmental Health (26). The construct overexpressing human MACROD1 was purchased from Addgene (#39041). The constructs overexpressing the catalytic domain of human PARP1 was a gift from Dr. Lee Kraus, University of Texas Southwest Medical Center (27). The shRNA constructs for SIRT1 (TRCN0000018979, TRCN0000018983) and DBC1 (TRCN0000053723 and TRCN0000053725) were both in pLKO.1 vector and purchased from Open Biosystems. The control shRNA for both SIRT1 and DBC1 was a TRC lentiviral pLKO.1 vector (# RHS4080). The siRNAs for human DBC1 (sc-72274), human PARP1 (sc-29437) and control siRNA (sc-36869) were from Santa Cruz.

3. Cell Culture, Transfection and Infection

293T, MCF-7, DBC1 wild type and knockout MEFs (a gift from Dr. Eduardo N. Chini from Mayo Clinic) were cultured in Dulbecco's modified Eagle's medium (DMEM, Mediatech, Inc., Herndon, Va.) supplemented with 10% fetal bovine serum (Gemini Bio-products, Woodland, Calif.) with the presence of penicillin and streptomycin (Corning, Manassas, Va.). Retroviruses expressing wild-type or mutant Flag-DBC1 proteins were produced by transfecting 293T cells with plasmids encoding VSV-G, Gag-Pol, and pMSCVpuro-Flag-DBC1 constructs using Lipofectamine® 2000 according to the manufacturer's instructions. Media was changed the day after transfection, and virus-containing media was harvested between 48 and 72 hours post-transfection and filtered through a 0.45 mm filter (Corning, Manassas, Va.). The filtered media was incubated with the target cells in the presence of 5 μg/mL polybrene (Sigma) and selection started using puromycin (2 μg/mL) 48 hrs post-infection. Lentivirus for knocking down DBC1 or SIRT1 was produced by transfecting 293T with psPAX2 (Addgene plasmid #12260), pMD2.G (Addgene plasmid #12259) and shRNA constructs using Lipofectamine® 2000. The virus harvest, infection and selection were same as described for retrovirus production. The transfections of siRNA were performed using Lipofectamine® RNAiMAX, according to the manufacturer's instructions.

The human primary fibroblast cells were cultured in Dulbecco's modified Eagle's medium supplemented with 15% fetal bovine serum in a low oxygen incubator (3% oxygen, 5% CO₂, 37° C.).

4. Immunoprecipitation

Protein extracts from 293T or mouse liver tissues were lysed in ice-cold buffer (150 mM NaCl, 1 mM EDTA, 1 mM EGTA, 1% Triton X-100, 0.5% NP-40, 10 mM Tris HCl, pH 7.4) supplemented with protease inhibitors cocktail cOmplete tablets (Roche) and phosphatase inhibitor cocktail 2 and 3 (Sigma). Protein concentrations were determined by the Bradford protein assay (Bio-rad). Flag-M2 agarose beads or anti-V5 agarose affinity gel (Sigma) were mixed with the lysate supernatant. Immunoprecipitation was allowed to proceed for 2 hours up to overnight at 4° C. with gentle rotation. After 4 washes with lysis buffer, proteins were either directly boiled in SDS-PAGE sample buffer or eluted from the agarose beads using 3× FLAG peptides (Sigma).

5. Immunoblotting

Cell lysates or Co-IP samples were run on homemade 10% or 4-20% gradient pre-cast SDS-PAGE gels (Bio-Rad) under reducing conditions, and then transferred to a polyvinylidene difluoride (PVDF) membrane (Millipore). Membranes were blocked with 5% non-fat dry milk in TBS-Tween (10 mM Tris HCl, pH 7.5, 150 mM NaCl, and 0.1% Tween-20). Antibodies were used at the following concentrations: anti-SIRT1 (Santa Cruz, SC-15404) at 1:500, anti-DBC1 (Bethyl Labotatories, A300-434A) at 1:1000, anti-PARP1 (Cell Signaling, #9542L) at 1:1000, anti-γH2AX (Abcam, ab2893) at 1:1000, anti-H2AX (Abcam, ab11175) at 1:1000, anti-NMNAT1 (Abcam, ab45548) at 1:1000, anti-GAPDH (Millipore, MAB374) at 1:3000, anti-V5 (Invitrogen, R960-25) at 1:3000, anti-beta-tubulin (Upstate, 05-661) at 1:1000, anti-α-actin (Millipore, MAB1501R) at 1:2000, anti-Flag (Sigma, F7425) at 1:3000, anti-PARG (Abcam, ab16060) at 1:1000, p53 (Calbiochem, OP43) at 1:1000, RAD51 (Calbiochem, PC130) at 1:1000, p21 (Neomarker-Labvision-Thermal Fisher, RB-032-P1) at 1:1000, SIRT6 (Cell signaling, D8D12) at 1:1000, Streptavidin-HRP at 1:1000 (Trevigen #4800-30-06), anti-PAR (Trevigen, #4335-MC-100; Abcam, ab14459) at 1:1000 and anti-PARP2 (Santa Cruz, SC-393310) at 1:200 overnight at 4° C. The antibodies ATM, ATR, BRCA1, Chk1, Chk2, DNA-PKs and XRCC1 were all from the Bethyl Laboratories. Phospho-Chk1, phospho-Chk2 and phosphor-p53 antibodies were from a DNA Damage Antibody Sampler Kit (Cell Signaling #9947). Secondary antibodies were horseradish peroxidase-coupled sheep anti-mouse IgG (GE Healthcare, UK), donkey anti-rabbit IgG (GE Healthcare, UK). Amersham™ ECL and Amersham Select ECL western blotting detection systems (GE Healthcare, UK) were used to develop signals. Quantifications of images from western blot films were performed using ImageJ (National Institutes of Health, Bethesda, Md.).

6. PARP1-DBC1 Dissociation Assays

Equal aliquots of 293T cell lysates with over-expressing Flag-DBC1 were immunoprecipitated using Flag-M2 agarose beads as described above. After four brief washes with lysis buffer, the beads aliquots were incubated with the freshly dissolved NAD⁺ or other chemicals for 1 hr at 4° C. with gentle rotation then centrifuged (5000 rpm, 5 min). After completely removing supernatant, the beads were boiled in SDS loading buffer, analyzed by SDS-PAGE, and probed with antibodies.

7. NAD⁺ Quantification

NAD⁺ quantification was conducted with an NAD/NADH Quantification Kit (Biovision, Milpitas, Calif.) following the manufacturer's instructions and normalized to soluble protein content.

8. 32P-NAD⁺ Binding Assays

Empty vector (6 μg), wild type, DBC1_(Q391A) and DBC1_(Δ354-396) (pcDNA 3.1 vector with V5/his tag) were transfected into 293T cells in 15 cm petri dishes separately, followed by IP using anti-V5 agarose gel as described above. After immunoprecipitation, 1/8 of the purified DBC1 protein bound to beads was boiled in SDS loading buffer and assessed for protein input by dot blotting. The remainder of the protein was incubated with cold NAD⁺ (1 μM), 8 μCi ³²P NAD⁺ (PerkinElmer) in 50 μl incubation buffer (50 mM Tris HCl, 150 mM NaCl and 10 mM DTT, pH7.4) for 2 hrs at 4° C. with gentle rotation. Beads were then washed in 1 ml of the same incubation buffer 3 times, centrifuged, and eluted in 25 μl of incubation buffer with 10 μg/ml V5 peptides on ice for 30 min with occasional shaking. Each elutant (5 μl) was spotted on filter paper and assessed by autoradiography.

9. Biotin-NAD⁺ Binding Assays

Lysates of 293T cells expressing Flag-DBC1 or V5/his-DBC1 were prepared as described above and bound to an anti-Flag high sensitivity M2 coated 96-well plate (Sigma) or His-Select® high sensitivity nickel coated 96-well plate (Sigma) by incubating for 3-4 hrs at 4° C., then washed three times with lysis buffer. Biotin-NAD⁺ (Trevigen), or specified molecules were incubated in the plates overnight at 4° C. After washing twice with PBS (pH 7.4) and twice with PBS-T (0.1% Triton X-100), streptavidin-HRP (Trevigen, 1:500) in PBS-T was added to each well and incubated for 1 hr at room temperature. After washing twice with PBS (pH 7.4) and twice with PBS-T, 100 μl of PeroxyGlow™ A and B chemiluminescent substrates (Trevigen) mixture (1:1) was added into each well for 1 min followed by immediate quantification of chemiluminescence on a EnSpire 2300 Multi-label reader (Perkin Elmer). Binding curves were calculated using the “one site, specific binding” formula of GraphPad.

10. Cell Survival

The CellTiter 96® Aqueous One Solution Cell Proliferation Assay (MTS) kit from Promega was used to measure cell survival after treating cells with paraquat for 24 hrs, according to manufacturer's instructions. The absorbance was measured using an EnSpire 2300 Multi-label reader (Perkin Elmer).

11. PARP1 Activity Assay

PARP1 was immunoprecipitated from cell or tissue extracts and activity was determined by a Universal Chemiluminescent PARP Assay Kit (Trevigen, #4676-096-K) that is based on HRP-streptavidin-mediated detection of biotin-labelled PAR. Luminescence was measured on an EnSpire 2300 Multi-label reader (Perkin Elmer).

12. Comet Assay

The CometAssay® kit (Trevigen) was used to detect DNA fragmentation in DBC1 knockdown 293T cells. After treatment with paraquat for 24 hrs, the cells were gently harvested and embedded in an agarose layer on microscope slides provided by the kit. Cells were lysed and DNA was electrophoresed for 30 min at 1 Volt/cm in alkaline conditions. Tails were visualized at a magnification of 200× using a Nikon Eclipse Ti microscope. The comet analysis open software casp 1.2.3b1 was used (casplab.com) to analyze randomly chosen nuclei (n>50) per group.

13. 8-OHdG DNA Damage Quantification

The OxiSelect™ oxidative DNA damage Elisa kit (Cell Biolabs) was used to detect 8-OHdG in mice livers after irradiation. Genomic DNA was extracted from liver using a DNeasy blood and tissue kit (Qiagen).

14. Gene Expression Analysis

MCF-7 Cells were trypsinized and washed in PBS before RNA was extracted using an RNeasy Mini Kit (Qiagen) and quantified using a NanoDrop 1000 spectrophotometer (Thermo Scientific). The cDNA synthesis was performed with iScript™ cDNA Synthesis Kit (Bio-Rad). Quantitative RT-PCR reactions were performed using LightCycler® 480 SYBR Green Master (Roche) on a LightCycler® 96 Real-Time PCR System (Roche). Calculations were performed using GeneEx qPCR data analysis software from Bio-Rad. Gene expression was normalized to housekeeping gene HPRT. Primers used for qPCR:

HPRT: TGCTGAGGATTTGGAAAGGG and ACAGAGGGCTACAATGTGATG; ABHD2: CACCTCTCTGAGCCTGTTCC and CGCAGATGTTCAGCAATGTT; TMSNB: TCCCAACAGCAGATTTCGAC and GCCAGGGAACATAGGTGAGA; PEG10: CAAGCCACCACCAGGTAGAT and GAGGCACAGGTTCAGCTTTC; NELL2: TGAAGGGAACCACCTACC and ATTTGCCATCCACATACG.

15. Mouse Handling and Treatment

C57BL/6J mice were obtained from the National Institutes of Aging (Bethesda, Md.) or The Jackson Laboratory (Bar Harbor, Me.). Treatment with PBS, NMN (i.p. 500 mg/kg/day) or Olaparib (i.p. 100 mg/kg/day) has been described previously (28). Olaparib (Selleckchem) was first dissolved in DMSO as a stock solution and diluted to final concentrations with the vehicle 10% w/v 2-hydroxypropyl-b-cyclodextrin in PBS prior to injection (Sigma, H107-5G). Mice were allowed to acclimatize to the facility for at least three weeks and all animal procedures were in accordance with the animal care and use policies of the IACUC committee at Harvard Medical School.

16. Protein Sequence Analysis, Structural Modeling and Docking

Iterative profile searches with the PSI-BLAST program (29) were used to retrieve homologous sequences from the protein non-redundant (NR) database at National Center for Biotechnology Information (NCBI). Multiple sequence alignments were built using the Kalign (30) and Promals (31) programs, followed by careful manual adjustments based on profile-profile alignment derived using the HHpred program (32), secondary structure prediction using the Jpred program (33) and using structural alignments. The Modeller9v11 program (34) was utilized for homology modeling the 3-dimentional structure of DBC1-NHD by using multiple PDB templates including Shewanella oneidensis NrtR (3gz5), Aquifex aeolicus Nudix hydrolase (2yyh), Caenorhabditis elegans AP4A hydrolase (1ktg), Mycobacterium tuberculosis ADPr pyrophosphatase (1mk1), and Escherichia coli GDP mannose hydrolase (1rya). In these low-sequence-identity cases, sequence alignment is the most important factor affecting the quality of the model (35). Alignments were therefore carefully built and cross-validated on the basis of information from HHpred and DaliLite programs, then edited manually using secondary structure information. The model was further refined using KoBaMIN (36). Autodock Vina was implemented in PyRx (http://pyrx.sorceforge.net) for molecular docking analysis, followed by a docked configuration that was based on the known nucleotide binding modes of Nudix enzyme-substrate complexes.

17. Immunohistochemistry and Immunofluorescence

The fresh frozen tissues were sectioned on a Minotome Cryostat (International Equipment Co. USA), fixed in pre-cooled acetone (−20° C.) for 10 min, rinsed in ice-cold PBS buffer (pH 7.4) 3 times for 5 min, then incubated in H₂O₂ solution in PBS (0.3% v/v) at room temperature for 10 min to block endogenous peroxidase activity, followed by rinsing in PBS 3 times for 5 min. After incubating with blocking buffer (1% fetal bovine serum in PBS with 0.05% Tween 20) in a humidified chamber at room temperature for 1 hr, the slides were incubated with γ-H2AX antibody (1:200 dilution, Cell signaling, #2577) in blocking buffer for 1 hr at room temperature, rinsed with PBS for 3 times for 5 min. Anti-rabbit-Horseradish Peroxidase (GE Healthcare, #NA934) was applied as secondary antibody (1:500 diluted in blocking buffer) at room temperature for 1 hr in a humidified chamber. After rinsing with PBS for 3 times for 5 min, freshly made DAB substrate was applied (Thermo Scientific, #34002, USA) for 5 min, followed by counterstaining using Hematoxylin (Mayer's Hematoxylin, Sigma #26043-05) for 2 min and then rinsing in tap water for 15 min before mounting. For immunofluorescence, nuclei were detected by DAPI (Vectashield from Vector Lab, #H-1200) and the γ-H2AX antibody (Cell signaling, #2577) was applied at a 1:200 dilution, then detected using an Alexa Flour ° 488 conjugated goat anti-rabbit secondary antibody (Life technology, #A-11034, 1:500 dilution).

18. Blue Native PAGE

The human PARP1-ACAT (residue 1 to 654) and human DBC1-NHD (residue 239 to 553) sequences were cloned into a modified pET19 vector and expressed as fusion proteins containing a N-terminal His_(x6)-SUMO tag in E. coli Codon+ using an auto-induction method overnight at 20° C. in TB medium supplemented with lactose (0.2% v/v). Both proteins were purified by affinity chromatography (His-Trap column, GE Healthcare) and size-exclusion chromatography (Superdex 200, GE Healthcare). For DBC1, the N-terminal tag was digested with SUMO protease at a protein/protein ratio of 1/100 (w/w) overnight at 4° C. and a second affinity chromatography was performed to separate the SUMO tag and protease from the target protein. Purified PARP1-ACAT and DBC1-NHD proteins were incubated for 30 min on ice prior to addition of glycerol (20% v/v final concentration) and loaded on a two-layer blue native page (5% and 12.5% acrylamide for the stacking and resolving layers, respectively). The blue native PAGE was then run at 4° C. for 2-3 hours at 200V. Marker bands at 240, 67 and 45 kDa corresponding to catalase, bovine serum albumin, and albumin from chicken egg white, respectively, were used to assess molecular weights.

19. DNA Repair Reporter Assays and FACS Analysis

In vivo DNA repair efficiency was measured as described (37). Reporter plasmids for measuring NHEJ or HR repair efficiency were linearized by HindIII (NEB) and purified using QIAquick gel extraction kit (Qiagen). Linearized reporter plasmids (0.5 μg) were co-transfected with pDsRed-express-DR (1.5 μg) using Lipofectamin 2000. Cells were treated with paraquat or 3-AB in 24 hrs post-transfection.

Example 2: A Conserved NAD+ Binding Pocket that Regulates Protein-Protein Interactions During Aging

The protein Deleted in Breast Cancer 1 (DBC1) is one of the most abundant, yet enigmatic proteins in mammals (M. Wang et al. Proteomics 15, 3163-3168 (2015); S. M. Armour et al. Mol. Cell. Biochem. 33, 1487-1502 (2013)), with a conserved domain similar to Nudix hydrolases that hydrolyze nucleoside diphosphates but lacking catalytic activity due to the absence of key catalytic residues (V. Anantharaman et al. Cell cycle 7, 1467-1472 (2008); A. S. Mildvan et al. Arch. Biochem. Biophys. 433, 129-143 (2005); J. P. Gagne et al. Nucleic Acids Res. 36, 6959-6976 (2008)).

DBC1 is known to inhibit SIRT1 (J. E. Kim et al. Nature 451, 583-586 (2008)). Thus, it was tested whether DBC1 might also inhibit PARP1 as a way to co-regulate these two major NAD⁺-responsive pathways. In human embryonic kidney 293T (293T) cells, a SIRT1-independent interaction between DBC1 and PARP1 was detected (FIG. 1, Panel (A) and FIG. 5, Panels (A) and (B)). The PARP1 inhibitors PJ-34 or 3-aminobenzamide (3-AB) had no effect on the interaction (FIG. 5, Panel (C)), nor did over-expression of the ADP-ribose hydrolase MACRO Domain containing 1 (MACROD1) (FIG. 5, Panel (D)), or the PARP1 catalytic mutant, PARP1-E988K (FIG. 5, Panel (E)). Thus, PARP1-DBC1 binding is independent of PARP1 catalytic activity.

The PARP1-DBC1 complex was abrogated by NAD⁺ in a concentration-dependent manner, whereas the SIRT1-DBC1 interaction was unaffected within physiological ranges of NAD⁺ (H. Yang et al., Cell 130, 1095-1107 (2007)) except at 500 μM (FIG. 1, Panel (B)). This effect was surprisingly specific: 200 μM of nicotinamide mononucleotide (NMN), nicotinamide riboside (NR), adenosine, adenosine triphosphate (ATP), ADP-ribose (ADPr) or 500 μM of nicotinamide (NAM) and its structural analogue 3-AB (2 mM), had no effect on the PARP1-DBC1 complex, and NADH (200 μM) or adenine (200 μM), were less effective than NAD⁺ (FIG. 1, Panel (C) and FIG. 6, Panels (A) and (C)).

DBC1 mutants lacking regions outside the NHD (DBC1₁₋₅₀₀ and DBC1₂₄₃₋₉₂₃) behaved similarly to full-length (FIG. 1, Panel (C)), while MACROD1, poly-ADP-ribose glycohydrolase (PARG) (FIG. 6, Panel (D)), or PARP1 inhibitors (FIG. 5, Panel (C)) had no effect. PARP1-E988K behaved similarly to the wild-type (FIG. 5, Panel (E) and FIG. 6, Panel (E)). Carbanicotinamide adenine dinucleotide (Carba-NAD), a non-reactive PARP1 substrate, abrogated the complex (FIG. 6, Panel (F)). Thus, disruption of the PARP1-DBC1 complex by NAD⁺ does not require NAD⁺ cleavage or a covalently attached ADP-ribose.

In HEK293T cells, FK866, an inhibitor of NAD⁺ biosynthesis (M. Hasmann et al. Cancer Res. 63, 7436-7442 (2003)), increased the PARP1-DBC1 interaction (FIG. 1, Panel (D)), as did depletion of NAD⁺ by genotoxic stress (FIG. 7, Panel (A)). Interventions that increased NAD⁺ abundance (J. Yoshino et al. Cell Metab. 14, 528-536 (2011); F. Berger et al. J Biol. Chem. 280, 36334-36341 (2005)) decreased the PARP1-DBC1 interaction (FIG. 1, Panels (E) and (F) and FIG. 7, Panel (B)). The SIRT1-DBC1 interaction was slightly diminished by FK866, possibly through the sequestration of DBC1 by PARP1 (FIG. 7, Panel (B)). Together, these data indicate that NAD⁺ inhibits PARP1-DBC1 complex formation in cells.

To better understand the mechanism by which NAD⁺ inhibits complex formation, the DBC1 domain necessary for interaction with PARP1 was identified. A truncated version of DBC1 lacking an NHD conserved region (DBC1_(Δ354-396)) had impaired PARP1 binding in cells (FIG. 8, Panels (A) and (D)), whereas a recombinant DBC1 mutant covering NHD domain (DBC1-NHD, residues 243-553) bound to a truncated PARP1 lack of catalytic domain (PARP1-ΔCAT, residues 1-654) (FIG. 9, Panels (A) and (B)) and was not abrogated by NAD⁺, indicating that residues outside the minimal NHD domain may be necessary for NAD⁺ to dissociate the complex.

DBC1 interacted with the Breast Cancer 1 (BRCA1)C-Terminal (BRCT) domain of PARP1 (FIG. 10, Panel (A)) (P. Bork et al. FASEB 111, 68-76 (1997)) but not with the PARP1 catalytic domain or PARP2, which lacks a BRCT domain (FIG. 10, Panels (B) and (D)). A BRCT-deficient PARP1 has higher activity than wild-type (FIG. 10, Panels (E) and (F)), together indicating PARP1-DBC1 is mediated by contacts between the NHD and PARP1-BRCT.

An atomic resolution homology model was generated for the human DBC1-NHD based on five known crystal structures of Nudix domains from other proteins (FIG. 2, Panel (A), FIG. 11 and Methods). NAD⁺ had the best fit of all riboside nucleotides. Substitutions of the amino acids predicted to alter NAD⁺ binding inhibited PARP1-DBC1 binding either slightly (K353A and P366A) or dramatically (Q391A) (FIG. 2, Panel (B) and FIG. 12, Panels (A) and (B)). Radio-labeled or biotin-labeled NAD⁺ directly bound to DBC1 (FIG. 2, Panels (C) and (D)) and was competed off with unlabeled NAD⁺ (FIG. S9, A to D). Partial deletion of the NHD (DBC1_(Δ354-396)) or Q391A (DBC1_(Q391A)) reduced NAD⁺ binding, whereas N-terminal and C-terminal truncations did not (FIG. 2, Panels (C) and (D), and FIG. 13, Panel (E)). Mutation of C387, a residue close to Q391 on the same helix (FIG. 2, Panel (A)), also decreased NAD⁺ binding (FIG. 2, Panel (D)) and reduced the responsiveness of the PARP1-DBC1 complex to NAD⁺ (FIG. 2, Panel (E)).

PARP1 activity was inhibited by DBC1 in vitro (FIG. 3, Panel (A)). In cells, knocking down DBC1 increased both PAR concentrations before and after exposure to paraquat, H₂O₂, or etoposide (FIG. 3, Panel (B) and FIG. 14, Panels (A) to (D)) and the abundance of mRNAs positively regulated by PARP1 (T. Zhang et al. J. Biol. Chem. 287, 12405-12416 (2012); R. Krishnakumar et al. Mol. Cell 39, 736-749 (2010)). Reintroduction of wild-type DBC1 reduced PARP1 activity and partially restored gene expression whereas DBC1_(Q391A) had no effect (FIG. 3, Panel (C) and FIG. 14, Panels (E) to (F)). Reducing DBC1 lowered the abundance of the phosphorylated form of histone H2AX (γ-H2AX) (FIG. 3, Panel (D)), reduced DNA fragmentation (FIG. 3, Panel (E) and FIG. 15, Panel (A)), increased cell survival post-paraquat (FIG. 15, Panel (B)), and increased both non-homologous end-joining (NHEJ) and homologous recombination (HR) pathways in a PARP1-dependent manner (FIG. 3, Panel (F) and FIG. 15, Panels (C)). Similarly, NMN treatment reduced the number of γH2AX foci in paraquat-treated primary human fibroblasts (FIG. 3, Panel (G) and FIG. 16). No other major DNA repair proteins appeared to change their interactions with PARP1-DBC1 complex in the presence of NMN or DNA damage (FIG. 17, Panels (A) to (B)), though other interactions cannot be ruled out. These results are consistent with a model in which binding of NAD⁺ to the DBC1 NHD regulates the two major pathways of DNA repair.

DNA repair declines with age (V. Gorbunova et al. Nucleic Acids Res. 35, 7466-7474 (2007)) in concert with lower PARP1 activity (K. Grube et al. Proc. Natl. Acad. Sci. U.S.A. 89, 11759-11763 (1992)). The data presented herein indicated a cause may be increased binding of DBC1 to PARP1 as NAD⁺ levels decline during aging. To test this, the effect of NMN treatment was examined on young and old mice. Hepatic NAD⁺ concentrations were lower in old mice (FIG. 4, Panel (A)), coincident with a higher amount of the DBC1-PARP1 complex (FIG. 4, Panel (B)) and an increase in γH2AX staining (FIG. 4, Panel (C), and FIG. 18). A week of NMN treatment (i.p. 500 mg/kg/d) increased hepatic NAD⁺ concentrations, disrupted the PARP1-DBC1 complex in young (FIG. 19, Panels (A) to (B)) and old mice (FIG. 4, Panels (D) to (E)), and reduced the abundance of γH2AX in old mice (FIG. 4, Panel (C) and FIG. 18).

In old mice, the low levels of PARP1 activity (FIG. 4, Panel (F), and FIG. 20, Panel (A)) and poor response to DNA damage (FIG. 20, Panel (B)). Knockout of DBC1 increased PARP1 activity (FIG. 4, Panel (G) and FIG. 20, Panel (C)). The reduced PARP1 activity in the old mice was restored by NMN (FIG. 4, Panel (F), and FIG. 20, Panel (D)) but not if PARP1 activity was inhibited (FIG. 20, Panels (E) and (F)). Total amounts of PARylation increased with age in the liver (L. Mouchiroud et al, Cell 154, 430-441 (2013)), possibly due to reduced PARG abundance (FIG. 21, Panel (A)). These data indicate that the decline in NAD⁺ during aging promotes binding of DBC1 to PARP1, which inhibits PARP1's ability to mediate DNA repair. Similar studies were conducted on old mice exposed to gamma irradiation. NMN treatment (FIG. 4, Panel (E)) reduced DNA damage (FIG. 4, Panel (H) and FIG. 21, Panel (B) to (C)) and protected against alterations in white blood cell counts, lymphocytes, and hemoglobin, even when given after irradiation (FIG. 4, Panels (I) and (J), FIG. 22, Panel (A) to (C)).

These data show that NAD⁺ has a third function in cells: to directly regulate protein-protein interactions. It was speculated that this mechanism evolved to allow a cell to adapt to fluctuations in NAD⁺ abundance without degrading it and, in the case of DBC1, to serve as a negative-feedback loop to prevent PARP1 from depleting NAD⁺ down to lethal levels during DNA damage (H. Yang et al. Cell 130, 1095-1107 (2007)) (FIG. 23). The data also provide an explanation for why DBC1 mutations are associated with cancers (M. Hamaguchi et al. Proc. Natl. Acad. Sci. U.S.A. 99, 13647-13652 (2002)) and indicate that assessing DBC1 status in tumors will help inform ongoing clinical trials of PARP1 inhibitors for treating cancer (M. W. Audeh et al. Lancet 376, 245-251 (2010)). Although it is unclear why NAD⁺ declines with age, this work provides a plausible explanation for why DNA repair capacity declines as mammals age (D. B. Lombard et al. Cell 120, 497-512 (2005)), pointing to NAD⁺ replenishment as a means of reducing the side effects of chemotherapy, protecting against radiation exposure, and slowing the natural decline in DNA repair capacity during aging.

Incorporation by Reference

All publications, including but not limited to patents and patent applications, cited in this specification, to the extent that they provide exemplary procedural or other details supplementary to those set forth herein, are specifically incorporated herein by reference as if each individual publication were specifically and individually indicated to be incorporated by reference herein as though fully set forth.

EQUIVALENTS

Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents of the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the following claims. 

1. A method for recovering from, treating, or preventing cancer in a subject in need thereof comprising administering an effective amount of a) nicotinamide mononucleotide, or an analog or derivative thereof; b) an agent that increases the level of nicotinamide mononucleotide, or an analog or derivative thereof; or c) both a) and b); to the subject to thereby modulate the activity of a biologically active polypeptide comprising a Nudix homology domain (NHD), or fragment thereof, or a nucleic acid encoding same.
 2. A method for recovering from, treating, or preventing aging or cell death in a subject in need thereof comprising administering an effective amount of a) nicotinamide mononucleotide, or an analog or derivative thereof; b) an agent that increases the level of nicotinamide mononucleotide, or an analog or derivative thereof; or c) both a) and b); to the subject to thereby modulate the activity of a biologically active polypeptide comprising a Nudix homology domain (NHD), or fragment thereof, or a nucleic acid encoding same.
 3. A method for recovering from, treating, or preventing radiation damage or radiation exposure or in a subject in need thereof comprising administering an effective amount of a) nicotinamide mononucleotide, or an analog or derivative thereof; b) an agent that increases the level of nicotinamide mononucleotide, or an analog or derivative thereof; or c) both a) and b); to the subject to thereby modulate the activity of a biologically active polypeptide comprising a Nudix homology domain (NHD), or fragment thereof, or a nucleic acid encoding same.
 4. A method for recovering from, treating, or preventing chemotherapy-induced damage or cellular senescence in a subject in need thereof comprising administering an effective amount of a) nicotinamide mononucleotide, or an analog or derivative thereof; b) an agent that increases the level of nicotinamide mononucleotide, or an analog or derivative thereof; or c) both a) and b); to the subject to thereby modulate the activity of a biologically active polypeptide comprising a Nudix homology domain (NHD), or fragment thereof, or a nucleic acid encoding same.
 5. A method for modulating DNA repair in a subject in need thereof comprising administering an effective amount of a) nicotinamide mononucleotide, or an analog or derivative thereof; b) an agent that increases the level of nicotinamide mononucleotide, or an analog or derivative thereof; or c) both a) and b); to the subject to thereby modulate the activity of a biologically active polypeptide comprising a Nudix homology domain (NHD), or fragment thereof, or a nucleic acid encoding same.
 6. A method for modulating cell proliferation or cell survival in a subject in need thereof comprising administering an effective amount of a) nicotinamide mononucleotide, or an analog or derivative thereof; b) an agent that increases the level of nicotinamide mononucleotide, or an analog or derivative thereof; or c) both a) and b); to the subject to thereby modulate the activity of a biologically active polypeptide comprising a Nudix homology domain (NHD), or fragment thereof, or a nucleic acid encoding same.
 7. The method of any of the preceding claims, wherein said biologically active polypeptide comprising a Nudix homology domain (NHD), or fragment thereof, binds nicotinamide dinucleotide, or an analog or derivative thereof.
 8. The method of any of the preceding claims, wherein the nicotinamide mononucleotide, or an analog or derivative thereof is nicotinamide adenine dinucleotide (NAD+).
 9. The method of claim 7, wherein said biologically active polypeptide comprising a Nudix homology domain (NHD), or fragment thereof, comprises the NHD domain of a protein from Deleted Breast Cancer 1 (DBC1), or a protein set forth in Table
 3. 10. The method of any of the preceding claims, wherein said biologically active polypeptide comprising a Nudix homology domain (NHD), or fragment thereof, has a defective, deleted, or mutated protein binding region which inhibits interaction with a protein involved in cancer, aging, radiation damage, DNA repair, cell proliferation, or cell survival.
 11. The method of any of the preceding claims, wherein said biologically active polypeptide comprising a Nudix homology domain (NHD), or fragment thereof, has a defective, deleted, or mutated protein binding region which inhibits interaction with a protein involved in regulating of gene expression, cell cycle, or both, wherein said protein comprises a protein set forth in Table
 4. 12. The method of claim 11, wherein the protein involved in regulating of gene expression is selected from the group consisting of proteins involved in RNA processing, translation, transcription, RNA splicing, spliceosomal complex, signal transduction, chromatin remodeling, immune response, trafficking, transcriptional regulation, and circadian cycle.
 13. The method of claim 11, wherein the protein involved in regulating cell cycle is selected from the group consisting of proteins involved in proliferation, chromosome condensation, chromosome segregation, DNA damage response, DNA replication, metabolism, nuclear trafficking, immune response.
 14. The method of any one of claims 10-13, wherein said protein is selected from the group consisting of PARP1, HNRPLL, SON, SUGP2, WDR33, THOC5, PUS1, SYMPK, THOC2, SART3, LSM4, PLRG1, SF3B2, SNRNP40, XAB2, ZCCHC8, PRPF8, PRPF4, POLR3B, POLR1A, POLR2D, POLR2A, SUPT5H, SUPT6H, GT3C4, EXOSC7, EIF4H, GTF3C5, MRPS23, SEP15, FKBP5, MRPS34, TPX2, TRIM27, USP7, UBE2K, STAG2, PDS5B, SMC4, PDS5A, NCAPG2, AKAP8, NUMA1, CEP170, POGZ, CTR9, TBLXR1, G3BP1, TLE1, SPIN1, COPS3, TLE3, GPS1, CSNK2A1, PRKDC, MSH3, MSH6, POLA1, TMPO, FEN1, PRIM2, CHTF18, AKAP8L, MLF2, SPATA5, ZMPSTE24, SMARCA2, SIRT1, SMARCA4, ARID1A, SMARCC2, KDM3B, ADNP, HDAC3, VPRBP, LCP1, KPNA3, TOMM40, IPO9, TIMM13, COBRA1, SAFB2, PELP1, TCEB2, CDK9, TROVE2, SRRT, PSPC1, FAM98B, GK, TXNRD1, NADKD1, NDUFS2, PCK2, CISD1, CYC1, and UQCRFS1, or combination thereof.
 15. The method of any one of claims 10-13, wherein said protein is selected from the group consisting of PARP1, MATR3, SRRT, NOP56, RIP1L1, UPF1, ZC3H14, HNRNPA0, LRPPRC, FARSA, EIF3D, MRPS22, NOP2, DNAJA2, NSUN2, DNAJA3, DDX5, DHX9, SFPQ, PPP1CB, PPP2R1A, BUB3, ILF3, ADAR, ISG15, NUP155, ZFR, ZC3H11A, KPNA4, KPNA1, KPNA3, KPNA6, ZNF326, SKIV2L2, SON, SUGP2, WTAP, PTBP1, PTBP3, CPSF1, RBM4, HNRNPUL2, SF1, SF3B1, PNN, ZCCHC8, SF3B3, CDC5L, PRPF8, SNRNP200, SAFB, PRMT5, WDR77, SUPT16H, SIRT1, SAP18, IKZF1, HCFC1, HDAC3, ZNF281, ZNF318, GIGYF2, RBM14, SAFB2, SPIN1, GTF21, MCM3, AKAP8L, TRIM28, PSMA2, PSME3, PSMB3, p53, USP11, SLC25A6, PFAS, CAD, SLC25A3, PFKL, ACLY, PPHLN1, RBM12B, and FLNA, or combination thereof.
 16. The method of any one of claims 1-6, wherein the agent is an NAD+ precursor.
 17. The method of claim 17, wherein the NAD+ precursor is nicotinamide mononucleotide (NMN) or a salt thereof, or a prodrug thereof, including crystalline and polymorphic form of same.
 18. The method of any one of claims 1-6, wherein the agent decreases or reduces nicotinamide.
 19. The method of any one of claims 1-6, wherein the agent increases the level or activity of an enzyme involved in NAD+ biosynthesis, or an enzymatically active fragment thereof, or a nucleic acid encoding an enzyme involved in NAD+ biosynthesis, or an enzymatically active fragment thereof.
 20. The method of claim 19, wherein the enzyme is mononucleotide adenylyl transferase (NMNAT) or nicotinamide phosphoribosyl transferase (NAMPT or NAMPRT).
 21. The method of any one of claims 1-6, further comprising administering an inhibitor that blocks or prevents protein-protein interaction or binding of said biologically active polypeptide comprising a NHD, or fragment thereof, with said protein involved in cancer, aging, radiation damage, DNA repair, cell proliferation, or cell survival.
 22. The method of any one of claims 16-21, wherein the agent is administered at a dose of between 0.5-5 grams per day.
 23. The method of any one of claims 16-21, wherein the agent is administered conjointly, prior to, or subsequent to administrating the biologically active polypeptide comprising the NHD, or fragment thereof, or a nucleic acid encoding same.
 24. The method of any of the preceding claims, wherein the agent or the biologically active polypeptide comprising the NHD, or fragment thereof, or a nucleic acid encoding same is administered in a pharmaceutically effective amount.
 25. The method of claim 24, wherein the pharmaceutically effective amount is provided as a pharmaceutical composition in combination with a pharmaceutically-acceptable excipient, diluent, or carrier.
 26. The method of any of the preceding claims, wherein the subject is a mammal or non-mammal.
 27. The method of claim 26, wherein the subject is a human. 